1
|
Jałbrzykowska K, Chrzanowska A, Roszkowski P, Struga M. The New Face of a Well-Known Antibiotic: A Review of the Anticancer Activity of Enoxacin and Its Derivatives. Cancers (Basel) 2022; 14:cancers14133056. [PMID: 35804828 PMCID: PMC9264829 DOI: 10.3390/cancers14133056] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 06/15/2022] [Accepted: 06/19/2022] [Indexed: 12/14/2022] Open
Abstract
Simple Summary Enoxacin is a second-generation quinolone with promising anticancer activity. In contrast to other members of the quinolone group, it exhibits an extraordinary cytotoxic mechanism of action. Enoxacin enhances RNA interference and promotes microRNA processing, as well as the production of free radicals. Interestingly, apart from its proapoptotic, cell cycle arresting and cytostatic effects, enoxacin manifests a limitation of cancer invasiveness. The underlying mechanisms are the competitive inhibition of vacuolar H+-ATPase subunits and c-Jun N-terminal kinase signaling pathway suppression. The newly synthesized enoxacin derivatives have shown a magnified cytotoxic effect with an emphasis on prooxidative, proapoptotic and microRNA interference actions. The mentioned mechanisms seem to contribute to a safer, more selective and more effective anticancer therapy. Abstract Enoxacin as a second-generation synthetic quinolone is known for its antibacterial action; however, in recent years there have been studies focusing on its anticancer potential. Interestingly, it turns out that compared to other fluoroquinolones, enoxacin exhibits uncommon cytotoxic properties. Besides its influence on apoptosis, the cell cycle and cell growth, it exhibits a regulatory action on microRNA biogenesis. It was revealed that the molecular targets of the enoxacin-mediated inhibition of osteoclastogenesis are vacuolar H+-ATPase subunits and the c-Jun N-terminal kinase signaling pathway, causing a decrease in cell invasiveness. Interestingly, the prooxidative nature of the subjected fluoroquinolone enhanced the cytotoxic effect. Crucial for the anticancer activity were the carboxyl group at the third carbon atom, fluorine at the seventh carbon atom and nitrogen at the eighth position of naphyridine. Modifications of the parent drug improved the induction of oxidative stress, cell cycle arrest and the dysregulation of microRNA. The inhibition of V-ATPase–microfilament binding was also observed. Enoxacin strongly affected various cancer but not normal cells, excluding keratinocytes, which suffered from phototoxicity. It seems to be an underestimated anticancer drug with pleiotropic action. Furthermore, its usage as a safe antibiotic with well-known pharmacokinetics and selectivity will enhance the development of anticancer treatment strategies. This review covers articles published within the years 2000–2021, with a strong focus on the recent years (2016–2021). However, some canonical papers published in twentieth century are also mentioned.
Collapse
Affiliation(s)
- Karolina Jałbrzykowska
- Chair and Department of Biochemistry, Medical University of Warsaw, Banacha 1, 02-097 Warszawa, Poland;
| | - Alicja Chrzanowska
- Chair and Department of Biochemistry, Medical University of Warsaw, Banacha 1, 02-097 Warszawa, Poland;
- Correspondence: (A.C.); (M.S.); Tel.: +48-22-5720693 (A.C. & M.S.)
| | - Piotr Roszkowski
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland;
| | - Marta Struga
- Chair and Department of Biochemistry, Medical University of Warsaw, Banacha 1, 02-097 Warszawa, Poland;
- Correspondence: (A.C.); (M.S.); Tel.: +48-22-5720693 (A.C. & M.S.)
| |
Collapse
|
2
|
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
|
3
|
Xu Q, Zhan P, Li X, Mo F, Xu H, Liu Y, Lai Q, Zhang B, Dai M, Liu X. Bisphosphonate-enoxacin inhibit osteoclast formation and function by abrogating RANKL-induced JNK signalling pathways during osteoporosis treatment. J Cell Mol Med 2021; 25:10126-10139. [PMID: 34651433 PMCID: PMC8572771 DOI: 10.1111/jcmm.16949] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 07/02/2021] [Accepted: 09/19/2021] [Indexed: 01/23/2023] Open
Abstract
Osteoporosis is an age‐related disease characterized by low mineral density, compromised bone strength and increased risk of fragility fracture. Most agents for treating osteoporosis focus primarily on anti‐resorption by inhibiting osteoclast activity. Bisphosphonate (BP) is a potent anti‐resorptive agent that has been used clinically for decades and is proven to be effective. However, BP has a variety of side effects and is far from being an ideal anti‐osteoporosis agent. BP selectively binds to calcium crystals, which are subsequently taken up or released by osteoclasts. Based on the action of BP, we previously demonstrated the inhibitory effect of a novel bone‐targeting BP derivative, bisphosphonate‐enoxacin (BE). In the current study, we used bone marrow‐derived osteoclast cultures to further assess the inhibitory effect of BE on osteoclastogenesis and employed reverse transcription PCR and real‐time PCR to examine expression of osteoclast‐specific genes. Additionally, we used bone resorption and F‐actin immunofluorescence assays to evaluate the effect of BE on osteoclast function and investigated the potential mechanisms affecting osteoclast differentiation and function in vitro. Furthermore, an ovariectomized (OVX) rat model was established to evaluate the therapeutic effects of BE on preventing bone loss. Results showed that BE exerted potent inhibitory effects on osteoclast formation and bone resorption by specifically abrogating RANKL‐induced JNK signalling, and that it preserved OVX rat bone mass in vivo without any notable side effects. Collectively, these results indicated that the BP derivative BE may have significant potential as a treatment for osteoporosis and other osteolytic diseases.
Collapse
Affiliation(s)
- Qiang Xu
- Department of Orthopedics, The First Affiliated Hospital of Nanchang University, Artificial Joints Engineering and Technology Research Center of Jiangxi Province, Nanchang, China
| | - Ping Zhan
- Department of Orthopedics, The First Affiliated Hospital of Nanchang University, Artificial Joints Engineering and Technology Research Center of Jiangxi Province, Nanchang, China
| | - Xiaofeng Li
- Department of Orthopedics, The First Affiliated Hospital of Nanchang University, Artificial Joints Engineering and Technology Research Center of Jiangxi Province, Nanchang, China
| | - Fengbo Mo
- Department of Orthopedics, The First Affiliated Hospital of Nanchang University, Artificial Joints Engineering and Technology Research Center of Jiangxi Province, Nanchang, China
| | - Huaen Xu
- Department of Orthopedics, The First Affiliated Hospital of Nanchang University, Artificial Joints Engineering and Technology Research Center of Jiangxi Province, Nanchang, China
| | - Yuan Liu
- Department of Orthopedics, The First Affiliated Hospital of Nanchang University, Artificial Joints Engineering and Technology Research Center of Jiangxi Province, Nanchang, China
| | - Qi Lai
- Department of Orthopedics, The First Affiliated Hospital of Nanchang University, Artificial Joints Engineering and Technology Research Center of Jiangxi Province, Nanchang, China
| | - Bin Zhang
- Department of Orthopedics, The First Affiliated Hospital of Nanchang University, Artificial Joints Engineering and Technology Research Center of Jiangxi Province, Nanchang, China
| | - Min Dai
- Department of Orthopedics, The First Affiliated Hospital of Nanchang University, Artificial Joints Engineering and Technology Research Center of Jiangxi Province, Nanchang, China
| | - Xuqiang Liu
- Department of Orthopedics, The First Affiliated Hospital of Nanchang University, Artificial Joints Engineering and Technology Research Center of Jiangxi Province, Nanchang, China
| |
Collapse
|
4
|
Dalhoff A. Selective toxicity of antibacterial agents-still a valid concept or do we miss chances and ignore risks? Infection 2021; 49:29-56. [PMID: 33367978 PMCID: PMC7851017 DOI: 10.1007/s15010-020-01536-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 10/04/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND Selective toxicity antibacteribiotics is considered to be due to interactions with targets either being unique to bacteria or being characterized by a dichotomy between pro- and eukaryotic pathways with high affinities of agents to bacterial- rather than eukaryotic targets. However, the theory of selective toxicity oversimplifies the complex modes of action of antibiotics in pro- and eukaryotes. METHODS AND OBJECTIVE This review summarizes data describing multiple modes of action of antibiotics in eukaryotes. RESULTS Aminoglycosides, macrolides, oxazolidinones, chloramphenicol, clindamycin, tetracyclines, glycylcyclines, fluoroquinolones, rifampicin, bedaquillin, ß-lactams inhibited mitochondrial translation either due to binding to mitosomes, inhibition of mitochondrial RNA-polymerase-, topoisomerase 2ß-, ATP-synthesis, transporter activities. Oxazolidinones, tetracyclines, vancomycin, ß-lactams, bacitracin, isoniazid, nitroxoline inhibited matrix-metalloproteinases (MMP) due to chelation with zinc and calcium, whereas fluoroquinols fluoroquinolones and chloramphenicol chelated with these cations, too, but increased MMP activities. MMP-inhibition supported clinical efficacies of ß-lactams and daptomycin in skin-infections, and of macrolides, tetracyclines in respiratory-diseases. Chelation may have contributed to neuroprotection by ß-lactams and fluoroquinolones. Aminoglycosides, macrolides, chloramphenicol, oxazolidins oxazolidinones, tetracyclines caused read-through of premature stop codons. Several additional targets for antibiotics in human cells have been identified like interaction of fluoroquinolones with DNA damage repair in eukaryotes, or inhibition of mucin overproduction by oxazolidinones. CONCLUSION The effects of antibiotics on eukaryotes are due to identical mechanisms as their antibacterial activities because of structural and functional homologies of pro- and eukaryotic targets, so that the effects of antibiotics on mammals are integral parts of their overall mechanisms of action.
Collapse
Affiliation(s)
- Axel Dalhoff
- Christian-Albrechts-University of Kiel, Institue for Infection Medicine, Brunswiker Str. 4, D-24105, Kiel, Germany.
| |
Collapse
|
5
|
Holliday LS, de Faria LP, Rody WJ. Actin and Actin-Associated Proteins in Extracellular Vesicles Shed by Osteoclasts. Int J Mol Sci 2019; 21:ijms21010158. [PMID: 31881680 PMCID: PMC6981389 DOI: 10.3390/ijms21010158] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 12/16/2019] [Accepted: 12/16/2019] [Indexed: 02/07/2023] Open
Abstract
Extracellular vesicles (EVs) are shed by all eukaryotic cells and have emerged as important intercellular regulators. EVs released by osteoclasts were recently identified as important coupling factors in bone remodeling. They are shed as osteoclasts resorb bone and stimulate osteoblasts to form bone to replace the bone resorbed. We reported the proteomic content of osteoclast EVs with data from two-dimensional, high resolution liquid chromatography/mass spectrometry. In this article, we examine in detail the actin and actin-associated proteins found in osteoclast EVs. Like EVs from other cell types, actin and various actin-associated proteins were abundant. These include components of the polymerization machinery, myosin mechanoenzymes, proteins that stabilize or depolymerize microfilaments, and actin-associated proteins that are involved in regulating integrins. The selective incorporation of actin-associated proteins into osteoclast EVs suggests that they have roles in the formation of EVs and/or the regulatory signaling functions of the EVs. Regulating integrins so that they bind extracellular matrix tightly, in order to attach EVs to the extracellular matrix at specific locations in organs and tissues, is one potential active role for actin-associated proteins in EVs.
Collapse
Affiliation(s)
- L. Shannon Holliday
- Department of Orthodontics, College of Dentistry, University of Florida, Gainesville, FL 32610, USA
- Correspondence:
| | - Lorraine Perciliano de Faria
- Department of Biomaterials and Oral Biology, School of Dentistry, University of São Paulo, São Paulo 01000, Brazil;
| | - Wellington J. Rody
- Department of Orthodontics and Pediatric Dentistry, Stony Brook University School of Dental Medicine, Stony Brook, NY 11794, USA;
| |
Collapse
|
6
|
Rody WJ, Chamberlain CA, Emory-Carter AK, McHugh KP, Wallet SM, Spicer V, Krokhin O, Holliday LS. The proteome of extracellular vesicles released by clastic cells differs based on their substrate. PLoS One 2019; 14:e0219602. [PMID: 31291376 PMCID: PMC6619814 DOI: 10.1371/journal.pone.0219602] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Accepted: 06/27/2019] [Indexed: 12/29/2022] Open
Abstract
Extracellular vesicles (EVs) from osteoclasts are important regulators in intercellular communication. Here, we investigated the proteome of EVs from clastic cells plated on plastic (clasts), bone (osteoclasts) and dentin (odontoclasts) by two-dimensional high performance liquid chromatography mass spectrometry seeking differences attributable to distinct mineralized matrices. A total of 1,952 proteins were identified. Of the 500 most abundant proteins in EVs, osteoclast and odontoclast EVs were 83.3% identical, while clasts shared 70.7% of the proteins with osteoclasts and 74.2% of proteins with odontoclasts. For each protein, the differences between the total ion count values were mapped to an expression ratio histogram (Z-score) in order to detect proteins differentially expressed. Stabilin-1 and macrophage mannose receptor-1 were significantly-enriched in EVs from odontoclasts compared with osteoclasts (Z = 2.45, Z = 3.34) and clasts (Z = 13.86, Z = 1.81) and were abundant in odontoclast EVs. Numerous less abundant proteins were differentially-enriched. Subunits of known protein complexes were abundant in clastic EVs, and were present at levels consistent with them being in assembled protein complexes. These included the proteasome, COP1, COP9, the T complex and a novel sub-complex of vacuolar H+-ATPase (V-ATPase), which included the (pro) renin receptor. The (pro) renin receptor was immunoprecipitated using an anti-E-subunit antibody from detergent-solubilized EVs, supporting the idea that the V-ATPase subunits present were in the same protein complex. We conclude that the protein composition of EVs released by clastic cells changes based on the substrate. Clastic EVs are enriched in various protein complexes including a previously undescribed V-ATPase sub-complex.
Collapse
Affiliation(s)
- Wellington J. Rody
- Department of Orthodontics and Pediatric Dentistry, Stony Brook University School of Dental Medicine, Stony Brook, NY, United States of America
- * E-mail: (WJR); (LSH)
| | - Casey A. Chamberlain
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, FL, United States of America
| | - Alyssa K. Emory-Carter
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, FL, United States of America
| | - Kevin P. McHugh
- Department of Periodontology, University of Florida College of Dentistry, Gainesville, FL, United States of America
| | - Shannon M. Wallet
- School of Dental Medicine, East Carolina University, Greenville, NC, United States of America
| | - Victor Spicer
- Manitoba Center for Proteomics and Systems Biology, Winnipeg, MB, Canada
| | - Oleg Krokhin
- Manitoba Center for Proteomics and Systems Biology, Winnipeg, MB, Canada
| | - L. Shannon Holliday
- Department of Orthodontics and Pediatric Dentistry, Stony Brook University School of Dental Medicine, Stony Brook, NY, United States of America
- Department of Anatomy & Cell Biology, University of Florida College of Medicine, Gainesville, FL, United States of America
- * E-mail: (WJR); (LSH)
| |
Collapse
|
7
|
Han G, Zuo J, Holliday LS. Specialized Roles for Actin in Osteoclasts: Unanswered Questions and Therapeutic Opportunities. Biomolecules 2019; 9:biom9010017. [PMID: 30634501 PMCID: PMC6359508 DOI: 10.3390/biom9010017] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 01/03/2019] [Accepted: 01/04/2019] [Indexed: 12/11/2022] Open
Abstract
Osteoclasts are cells of the hematopoietic lineage that are specialized to resorb bone. In osteoclasts, the actin cytoskeleton engages in at least two unusual activities that are required for resorption. First, microfilaments form a dynamic and structurally elaborate actin ring. Second, microfilaments bind vacuolar H⁺-ATPase (V-ATPase) and are involved in forming the V-ATPase-rich ruffled plasma membrane. The current review examines these two specialized functions with emphasis on the identification of new therapeutic opportunities. The actin ring is composed of substructures called podosomes that are interwoven to form a cohesive superstructure. Studies examining the regulation of the formation of actin rings and its constituent proteins are reviewed. Areas where there are gaps in the knowledge are highlighted. Microfilaments directly interact with the V-ATPase through an actin binding site in the B2-subunit of V-ATPase. This binding interaction is required for ruffled membrane formation. Recent studies show that an inhibitor of the interaction blocks bone resorption in pre-clinical animal models, including a model of post-menopausal osteoporosis. Because the unusual actin-based resorption complex is unique to osteoclasts and essential for bone resorption, it is likely that deeper understanding of its underlying mechanisms will lead to new approaches to treat bone disease.
Collapse
Affiliation(s)
- Guanghong Han
- Department of Stomatology, College and Hospital of Stomatology, Jilin University, Changchun 130021, China.
| | - Jian Zuo
- Department of Orthodontics, College of Dentistry, University of Florida, Gainesville, FL 32610, USA.
| | - Lexie Shannon Holliday
- Department of Orthodontics, College of Dentistry, University of Florida, Gainesville, FL 32610, USA.
- Department of Anatomy & Cell Biology, College of Dentistry, University of Florida, Gainesville, FL 32610, USA.
| |
Collapse
|
8
|
Enoxacin and bis-enoxacin stimulate 4T1 murine breast cancer cells to release extracellular vesicles that inhibit osteoclastogenesis. Sci Rep 2018; 8:16182. [PMID: 30385810 PMCID: PMC6212457 DOI: 10.1038/s41598-018-34698-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 10/23/2018] [Indexed: 12/21/2022] Open
Abstract
Enoxacin and its bone-seeking bisphosphonate derivative, bis-enoxacin, have recently captured attention as potential therapeutic agents for the treatment of cancer and bone disease. No differences in growth or survival of 4T1 murine breast cancer cells were detected at a concentration of 50 µM of enoxacin or bis-enoxacin. Growth was perturbed at higher concentrations. Both 50 µM enoxacin and bis-enoxacin stimulated increases in the number of GW/Processing bodies, but there were minimal changes in microRNA levels. Extracellular vesicles (EVs) released from 4T1 cells treated with 50 µM enoxacin or 50 µM bis-enoxacin stimulated proliferation of RAW 264.7 cells, and both significantly inhibited osteoclastogenesis in calcitriol-stimulated mouse marrow. EVs from 4T1 cells treated with enoxacin and bis-enoxacin displayed small reductions in the amount of microRNA (miR)-146a-5p and let-7b-5p. In marked contrast, miR-214-3p, which has been shown to regulate bone remodeling, was increased 22-fold and 30-fold respectively. We conclude that enoxacin and bis-enoxacin trigger the release of EVs from 4T1 cancer cells that inhibit osteoclastogenesis.
Collapse
|
9
|
Duan X, Yang S, Zhang L, Yang T. V-ATPases and osteoclasts: ambiguous future of V-ATPases inhibitors in osteoporosis. Theranostics 2018; 8:5379-5399. [PMID: 30555553 PMCID: PMC6276090 DOI: 10.7150/thno.28391] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 10/10/2018] [Indexed: 12/11/2022] Open
Abstract
Vacuolar ATPases (V-ATPases) play a critical role in regulating extracellular acidification of osteoclasts and bone resorption. The deficiencies of subunit a3 and d2 of V-ATPases result in increased bone density in humans and mice. One of the traditional drug design strategies in treating osteoporosis is the use of subunit a3 inhibitor. Recent findings connect subunits H and G1 with decreased bone density. Given the controversial effects of ATPase subunits on bone density, there is a critical need to review the subunits of V-ATPase in osteoclasts and their functions in regulating osteoclasts and bone remodeling. In this review, we comprehensively address the following areas: information about all V-ATPase subunits and their isoforms; summary of V-ATPase subunits associated with human genetic diseases; V-ATPase subunits and osteopetrosis/osteoporosis; screening of all V-ATPase subunits variants in GEFOS data and in-house data; spectrum of V-ATPase subunits during osteoclastogenesis; direct and indirect roles of subunits of V-ATPases in osteoclasts; V-ATPase-associated signaling pathways in osteoclasts; interactions among V-ATPase subunits in osteoclasts; osteoclast-specific V-ATPase inhibitors; perspective of future inhibitors or activators targeting V-ATPase subunits in the treatment of osteoporosis.
Collapse
Affiliation(s)
- Xiaohong Duan
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Department of Oral Biology, Clinic of Oral Rare and Genetic Diseases, School of Stomatology, the Fourth Military Medical University, 145 West Changle Road, Xi'an 710032, P. R. China
| | - Shaoqing Yang
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Department of Oral Biology, Clinic of Oral Rare and Genetic Diseases, School of Stomatology, the Fourth Military Medical University, 145 West Changle Road, Xi'an 710032, P. R. China
| | - Lei Zhang
- Center for Genetic Epidemiology and Genomics, School of Public Health, Medical College of Soochow University, 199 Renai Road, Suzhou, Jiangsu, P. R. China
| | - Tielin Yang
- Key Laboratory of Biomedical Information Engineering of Ministry of Education, and Institute of Molecular Genetics, School of Life Science and Technology, Xi'an Jiaotong University, 28 West Xianning Road, Xi'an 710049, People's Republic of China
| |
Collapse
|
10
|
Chellaiah MA, Ma T, Majumdar S. L-plastin phosphorylation regulates the early phase of sealing ring formation by actin bundling process in mouse osteoclasts. Exp Cell Res 2018; 372:73-82. [PMID: 30244178 DOI: 10.1016/j.yexcr.2018.09.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 09/05/2018] [Accepted: 09/19/2018] [Indexed: 10/28/2022]
Abstract
The process of sealing ring formation requires major actin filament reorganization. We previously demonstrated that an actin-bundling protein L-plastin has a role in the cross-linking of actin filaments into tight bundles and forms actin aggregates (denoted as nascent sealing zones). These nascent sealing zones mature into fully functional sealing rings. We have shown here that TNF-alpha signaling regulates the phosphorylation of serine-5 and -7 in L-plastin which increases the actin bundling capacity of L-plastin and hence the formation of nascent sealing zones in mouse osteoclasts. Using the TAT-mediated transduction method, we confirmed the role of L-plastin in nascent sealing zones formation at the early phase of the sealing ring assembly. Transduction of TAT-fused full-length L-plastin peptide significantly increases the number of nascent sealing zones and therefore sealing rings. But, transduction of amino-terminal L-plastin peptides consisting of the serine-5 and -7 reduces the formation of both nascent sealing zones and sealing rings. Therefore, bone resorption in vitro was reduced considerably. The decrease was associated with the selective inhibition of cellular L-plastin phosphorylation by the transduced peptides. Neither the formation of podosomes nor the migration was affected in these osteoclasts. Phosphorylation of L- plastin on serine 5 and -7 residues increases the F-actin bundling capacity. The significance of our studies stands on laying the groundwork for a better understanding of L-plastin as a potential regulator at the early phase of sealing ring formation and could be a new therapeutic target to treat bone loss.
Collapse
Affiliation(s)
- Meenakshi A Chellaiah
- Department of Oncology and Diagnostic Sciences Dental School, University of Maryland, Baltimore, Maryland.
| | - Tao Ma
- Department of Oncology and Diagnostic Sciences Dental School, University of Maryland, Baltimore, Maryland
| | - Sunipa Majumdar
- Department of Oncology and Diagnostic Sciences Dental School, University of Maryland, Baltimore, Maryland
| |
Collapse
|
11
|
Kuchuk O, Tuccitto A, Citterio D, Huber V, Camisaschi C, Milione M, Vergani B, Villa A, Alison MR, Carradori S, Supuran CT, Rivoltini L, Castelli C, Mazzaferro V. pH regulators to target the tumor immune microenvironment in human hepatocellular carcinoma. Oncoimmunology 2018; 7:e1445452. [PMID: 29900055 PMCID: PMC5993489 DOI: 10.1080/2162402x.2018.1445452] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 02/16/2018] [Accepted: 02/20/2018] [Indexed: 01/11/2023] Open
Abstract
Interfering with tumor metabolism is an emerging strategy for treating cancers that are resistant to standard therapies. Featuring a rapid proliferation rate and exacerbated glycolysis, hepatocellular carcinoma (HCC) creates a highly hypoxic microenvironment with excessive production of lactic and carbonic acids. These metabolic conditions promote disease aggressiveness and cancer-related immunosuppression. The pH regulatory molecules work as a bridge between tumor cells and their surrounding milieu. Herein, we show that the pH regulatory molecules CAIX, CAXII and V-ATPase are overexpressed in the HCC microenvironment and that interfering with their pathways exerts antitumor activity. Importantly, the V-ATPase complex was expressed by M2-like tumor-associated macrophages. Blocking ex vivo V-ATPase activity established a less immune-suppressive tumor microenvironment and reversed the mesenchymal features of HCC. Thus, targeting the unique cross-talk between tumor cells and the tumor microenvironment played by pH regulatory molecules holds promise as a strategy to control HCC progression and to reduce the immunosuppressive pressure mediated by the hypoxic/acidic metabolism, particularly considering the potential combination of this strategy with emerging immune checkpoint-based immunotherapies.
Collapse
Affiliation(s)
- Olga Kuchuk
- Unit of Immunotherapy of Human Tumors, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.,Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Alessandra Tuccitto
- Unit of Immunotherapy of Human Tumors, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.,Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Davide Citterio
- Hepatology and Liver Transplantation Unit, Department of Surgery, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Veronica Huber
- Unit of Immunotherapy of Human Tumors, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.,Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Chiara Camisaschi
- Unit of Immunotherapy of Human Tumors, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.,Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Massimo Milione
- Anatomic Pathology, Department of Pathology and Laboratory Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Barbara Vergani
- Consorzio MIA (Microscopy and Image Analysis), University of Milano-Bicocca, Milan, Italy
| | - Antonello Villa
- Consorzio MIA (Microscopy and Image Analysis), University of Milano-Bicocca, Milan, Italy
| | - Malcolm Ronald Alison
- Centre for Tumour Biology, Barts Cancer Institute, Charterhouse Square, London, EC1M 6BQ, United Kingdom
| | - Simone Carradori
- Department of Pharmacy, "G. D'Annunzio" University of Chieti-Pescara, Chieti, Italy
| | - Claudiu T Supuran
- Polo Scientifico, Department of Pharmaceutical Sciences, Sesto Fiorentino, Firenze, Italy
| | - Licia Rivoltini
- Unit of Immunotherapy of Human Tumors, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.,Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Chiara Castelli
- Unit of Immunotherapy of Human Tumors, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.,Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Vincenzo Mazzaferro
- Hepatology and Liver Transplantation Unit, Department of Surgery, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.,University of Milan, Italy
| |
Collapse
|
12
|
Holliday LS. Vacuolar H +-ATPases (V-ATPases) as therapeutic targets: a brief review and recent developments. ACTA ACUST UNITED AC 2017; 1. [PMID: 30957075 DOI: 10.21037/biotarget.2017.12.01] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Vacuolar H+-ATPases (V-ATPases) are multi-subunit enzymes that play housekeeping roles in eukaryotic cells by acidifying lysosomes, late endosomes, Golgi, and other membrane-bounded compartments. Beyond that, V-ATPases have specialized functions in certain cell types linked to diseases including osteoporosis and cancer. Efforts to identify strategies to develop inhibitors selective for V-ATPases that are involved in disease progression have been ongoing for more than two decades, but so far have not yielded a therapeutic agent that has been translated to the clinic. Recent basic science studies have identified unexpected roles for V-ATPases in nutrient and energy sensing, and renin/angiotensin signaling, which offer additional incentives for considering V-ATPases as therapeutic targets. This article briefly reviews efforts to utilize inhibitors of V-ATPases as drugs. Primary focus is on recent "rational" efforts to identify small molecule inhibitors of the V-ATPases that are selectively expressed in osteoclasts and cancer cells. Enoxacin and bis-enoxacin are two molecules that emerged from these efforts. These molecules block a binding interaction between V-ATPases and microfilaments that occurs in osteoclasts, but not most other cell types, which relates to the specialized function of V-ATPases in bone resorption. Enoxacin and bis-enoxacin have proven useful in the treatment of bone diseases and cancer in animal models and display therapeutic effects that are different, and perhaps better, than current drugs. These results provide evidence that agents targeting subsets of V-ATPases may prove useful in the clinic.
Collapse
Affiliation(s)
- L Shannon Holliday
- Departments of Orthodontics and Anatomy & Cell Biology, University of Florida College of Dentistry, Gainesville, Florida, USA
| |
Collapse
|
13
|
Banerjee S, Kane PM. Direct interaction of the Golgi V-ATPase a-subunit isoform with PI(4)P drives localization of Golgi V-ATPases in yeast. Mol Biol Cell 2017; 28:2518-2530. [PMID: 28720663 PMCID: PMC5597324 DOI: 10.1091/mbc.e17-05-0316] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 07/03/2017] [Accepted: 07/14/2017] [Indexed: 12/11/2022] Open
Abstract
PI(4)P directly interacts with the cytosolic domain of yeast Golgi vacuolar H+-ATPase (V-ATPase) a-isoform, Stv1, and the human Golgi a-subunit isoform. Lys-84 of Stv1 is essential for PI(4)P interaction, and localization of Stv1-containing V-ATPases in vivo requires the PI(4)P interaction. We propose that phosphatidylinositol binding exerts organelle-specific control over V-ATPases. Luminal pH and phosphoinositide content are fundamental features of organelle identity. Vacuolar H+-ATPases (V-ATPases) drive organelle acidification in all eukaryotes, and membrane-bound a-subunit isoforms of the V-ATPase are implicated in organelle-specific targeting and regulation. Earlier work demonstrated that the endolysosomal lipid PI(3,5)P2 activates V-ATPases containing the vacuolar a-subunit isoform in Saccharomyces cerevisiae. Here we demonstrate that PI(4)P, the predominant Golgi phosphatidylinositol (PI) species, directly interacts with the cytosolic amino terminal (NT) domain of the yeast Golgi V-ATPase a-isoform Stv1. Lysine-84 of Stv1NT is essential for interaction with PI(4)P in vitro and in vivo, and interaction with PI(4)P is required for efficient localization of Stv1-containing V-ATPases. The cytosolic NT domain of the human V-ATPase a2 isoform specifically interacts with PI(4)P in vitro, consistent with its Golgi localization and function. We propose that NT domains of Vo a-subunit isoforms interact specifically with PI lipids in their organelles of residence. These interactions can transmit organelle-specific targeting or regulation information to V-ATPases.
Collapse
Affiliation(s)
- Subhrajit Banerjee
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210
| | - Patricia M Kane
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210
| |
Collapse
|
14
|
Liu S, Zhu W, Li S, Ma J, Zhang H, Li Z, Zhang L, Zhang B, Li Z, Liang X, Shi W. Bovine parathyroid hormone enhances osteoclast bone resorption by modulating V-ATPase through PTH1R. Int J Mol Med 2015; 37:284-92. [PMID: 26647715 PMCID: PMC4716795 DOI: 10.3892/ijmm.2015.2423] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 12/01/2015] [Indexed: 11/17/2022] Open
Abstract
The vacuolar-type H+ adenosine triphosphatase (V-ATPase) plays an important role in cellular acidification and bone resorption by osteoclasts. However, the direct effect of bovine parathyroid hormone (bPTH) on V-ATPase has not yet been elucidated. The aim of the present study was to assess the effects of bPTH on V-ATPase and osteoclasts. Osteoclasts from bone marrow (BM)-derived monocytes of C57BL/6 mice were cultured with or without bPTH. The mRNA and protein expression levels of the V-ATPase a3-subunit and d2-subunit (by RT-qPCR and western blot analysis), V-ATPase activity (using the V type ATPase Activity Assay kit) and the bone resorption function of osteoclasts (by bone resorption assay) were examined following treatment with various concentrations of bPTH (0.1, 1.0, 10 and 100 ng/ml) alone or with bPTH and its inhibitor, bafilomycin A1. Furthermore, the expression of parathyroid hormone (PTH) receptors in osteoclasts was also detected. The results revealed that the mRNA and protein expression levels of V-ATPase a3-subunit and d2-subunit increased in a dose-dependent manner, paralleling the level of bPTH present. In addition, an increase in the concentration of bPTH was accompanied by the increased resorption capability of osteoclasts, whereas bone resorption was inhibited in the presence of bafilomycin A1. In addition, we confirmed the existence of parathyroid hormone 1 receptor (PTH1R) in osteoclasts using three different methods (RT-qPCR, western blot analysis and immunofluorescence staining). We found that bPTH enhanced the bone resorption capability of osteoclasts by modulating the expression of V-ATPase subunits, intracellular acidification and V-ATPase activity. Thus, we propose that PTH has a direct effect on osteoblasts and osteoclasts, and that this effect is mediated through PTH1R, thus contributing to bone remodeling.
Collapse
Affiliation(s)
- Shuangxin Liu
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| | - Weiping Zhu
- Department of Nephrology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, Guangdong 519000, P.R. China
| | - Sijia Li
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| | - Jianchao Ma
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| | - Huitao Zhang
- Department of Nephrology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, Guangdong 519000, P.R. China
| | - Zhonghe Li
- Department of Nephrology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, Guangdong 519000, P.R. China
| | - Li Zhang
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| | - Bin Zhang
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| | - Zhuo Li
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| | - Xinling Liang
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| | - Wei Shi
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| |
Collapse
|
15
|
Baldwin DA. A New Tool for in vivo Manipulation of Brain microRNA Levels: The Work of Smalheiser et al. (2014). Front Psychiatry 2015; 6:44. [PMID: 25941493 PMCID: PMC4403296 DOI: 10.3389/fpsyt.2015.00044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 03/13/2015] [Indexed: 11/22/2022] Open
|
16
|
Rivera MF, Chukkapalli SS, Velsko IM, Lee JY, Bhattacharyya I, Dolce C, Toro EJ, Holliday LS, Kesavalu L. Bis-enoxacin blocks rat alveolar bone resorption from experimental periodontitis. PLoS One 2014; 9:e92119. [PMID: 24638087 PMCID: PMC3956892 DOI: 10.1371/journal.pone.0092119] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 02/17/2014] [Indexed: 12/30/2022] Open
Abstract
Periodontal diseases are multifactorial, caused by polymicrobial subgingival pathogens, including Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia. Chronic periodontal infection results in inflammation, destruction of connective tissues, periodontal ligament, and alveolar bone resorption, and ultimately tooth loss. Enoxacin and a bisphosphonate derivative of enoxacin (bis-enoxacin) inhibit osteoclast formation and bone resorption and also contain antibiotic properties. Our study proposes that enoxacin and/or bis-enoxacin may be useful in reducing alveolar bone resorption and possibly bacterial colonization. Rats were infected with 10(9) cells of polymicrobial inoculum consisting of P. gingivalis, T. denticola, and T. forsythia, as an oral lavage every other week for twelve weeks. Daily subcutaneous injections of enoxacin (5 mg/kg/day), bis-enoxacin (5, 25 mg/kg/day), alendronate (1, 10 mg/kg/day), or doxycycline (5 mg/day) were administered after 6 weeks of polymicrobial infection. Periodontal disease parameters, including bacterial colonization/infection, immune response, inflammation, alveolar bone resorption, and systemic spread, were assessed post-euthanasia. All three periodontal pathogens colonized the rat oral cavity during polymicrobial infection. Polymicrobial infection induced an increase in total alveolar bone resorption, intrabony defects, and gingival inflammation. Treatment with bis-enoxacin significantly decreased alveolar bone resorption more effectively than either alendronate or doxycycline. Histologic examination revealed that treatment with bis-enoxacin and enoxacin reduced gingival inflammation and decreased apical migration of junctional epithelium. These data support the hypothesis that bis-enoxacin and enoxacin may be useful for the treatment of periodontal disease.
Collapse
Affiliation(s)
- Mercedes F. Rivera
- Department of Periodontology, College of Dentistry, University of Florida, Gainesville, Florida, United States of America
| | - Sasanka S. Chukkapalli
- Department of Periodontology, College of Dentistry, University of Florida, Gainesville, Florida, United States of America
| | - Irina M. Velsko
- Department of Periodontology, College of Dentistry, University of Florida, Gainesville, Florida, United States of America
| | - Ju-Youn Lee
- Department of Periodontology, College of Dentistry, University of Florida, Gainesville, Florida, United States of America
| | - Indraneel Bhattacharyya
- Department of Oral Diagnostic Sciences, College of Dentistry, University of Florida, Gainesville, Florida, United States of America
| | - Calogero Dolce
- Department of Orthodontics, College of Dentistry, University of Florida, Gainesville, Florida, United States of America
| | - Edgardo J. Toro
- Department of Orthodontics, College of Dentistry, University of Florida, Gainesville, Florida, United States of America
| | - L. Shannon Holliday
- Department of Orthodontics, College of Dentistry, University of Florida, Gainesville, Florida, United States of America
- Department of Anatomy and Cell Biology, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Lakshmyya Kesavalu
- Department of Periodontology, College of Dentistry, University of Florida, Gainesville, Florida, United States of America
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, Florida, United States of America
| |
Collapse
|
17
|
Marshansky V, Rubinstein JL, Grüber G. Eukaryotic V-ATPase: novel structural findings and functional insights. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:857-79. [PMID: 24508215 DOI: 10.1016/j.bbabio.2014.01.018] [Citation(s) in RCA: 127] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2013] [Revised: 12/25/2013] [Accepted: 01/27/2014] [Indexed: 02/06/2023]
Abstract
The eukaryotic V-type adenosine triphosphatase (V-ATPase) is a multi-subunit membrane protein complex that is evolutionarily related to F-type adenosine triphosphate (ATP) synthases and A-ATP synthases. These ATPases/ATP synthases are functionally conserved and operate as rotary proton-pumping nano-motors, invented by Nature billions of years ago. In the first part of this review we will focus on recent structural findings of eukaryotic V-ATPases and discuss the role of different subunits in the function of the V-ATPase holocomplex. Despite structural and functional similarities between rotary ATPases, the eukaryotic V-ATPases are the most complex enzymes that have acquired some unconventional cellular functions during evolution. In particular, the novel roles of V-ATPases in the regulation of cellular receptors and their trafficking via endocytotic and exocytotic pathways were recently uncovered. In the second part of this review we will discuss these unique roles of V-ATPases in modulation of function of cellular receptors, involved in the development and progression of diseases such as cancer and diabetes as well as neurodegenerative and kidney disorders. Moreover, it was recently revealed that the V-ATPase itself functions as an evolutionarily conserved pH sensor and receptor for cytohesin-2/Arf-family GTP-binding proteins. Thus, in the third part of the review we will evaluate the structural basis for and functional insights into this novel concept, followed by the analysis of the potentially essential role of V-ATPase in the regulation of this signaling pathway in health and disease. Finally, future prospects for structural and functional studies of the eukaryotic V-ATPase will be discussed.
Collapse
Affiliation(s)
- Vladimir Marshansky
- Center for Systems Biology, Program in Membrane Biology, Division of Nephrology, Simches Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA; Department of Medicine, Harvard Medical School, Boston, MA 02114, USA; Kadmon Pharmaceuticals Corporation, Alexandria Center for Life Science, 450 East 29th Street, New York, NY 10016, USA.
| | - John L Rubinstein
- Molecular Structure and Function Program, The Hospital for Sick Children Research Institute, University of Toronto, Toronto, ON M5G 1X8, Canada; Department of Biochemistry, University of Toronto, Toronto, ON M5G 1X8, Canada; Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1X8, Canada
| | - Gerhard Grüber
- Nanyang Technological University, Division of Structural Biology and Biochemistry, School of Biological Sciences, Singapore 637551, Republic of Singapore; Bioinformatics Institute, A(⁎)STAR, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
| |
Collapse
|
18
|
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
|
19
|
Toro EJ, Zuo J, Gutierrez A, Guiterrez A, La Rosa RL, Gawron AJ, Bradaschia-Correa V, Arana-Chavez V, Dolce C, Rivera MF, Kesavalu L, Bhattacharyya I, Neubert JK, Holliday LS. Bis-enoxacin inhibits bone resorption and orthodontic tooth movement. J Dent Res 2013; 92:925-31. [PMID: 23958763 DOI: 10.1177/0022034513501876] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
UNLABELLED Enoxacin inhibits binding between the B-subunit of vacuolar H(+)-ATPase (V-ATPase) and microfilaments, and also between osteoclast formation and bone resorption in vitro. We hypothesized that a bisphosphonate derivative of enoxacin, bis-enoxacin (BE), which was previously studied as a bone-directed antibiotic, might have similar activities. BE shared a number of characteristics with enoxacin: It blocked binding between the recombinant B-subunit and microfilaments and inhibited osteoclastogenesis in cell culture with IC50s of about 10 µM in each case. BE did not alter the relative expression levels of various osteoclast-specific proteins. Even though tartrate-resistant acid phosphatase 5b was expressed, proteolytic activation of the latent pro-enzyme was inhibited. However, unlike enoxacin, BE stimulated caspase-3 activity. BE bound to bone slices and inhibited bone resorption by osteoclasts on BE-coated bone slices in cell culture. BE reduced the amount of orthodontic tooth movement achieved in rats after 28 days. Analysis of these data suggests that BE is a novel anti-resorptive molecule that is active both in vitro and in vivo and may have clinical uses. ABBREVIATIONS BE, bis-enoxacin; V-ATPase, vacuolar H(+)-ATPase; TRAP, tartrate-resistant acid phosphatase; αMEM D10, minimal essential media, alpha modification with 10% fetal bovine serum; SDS-PAGE, sodium dodecyl sulfate-polyacrylamide gel electrophoresis; RANKL, receptor activator of nuclear factor kappa B-ligand; NFATc1, nuclear factor of activated T-cells; ADAM, a disintegrin and metalloprotease domain; OTM, orthodontic tooth movement.
Collapse
Affiliation(s)
- E J Toro
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, FL 32610, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Parsons LS, Wilkens S. Probing subunit-subunit interactions in the yeast vacuolar ATPase by peptide arrays. PLoS One 2012; 7:e46960. [PMID: 23071676 PMCID: PMC3470569 DOI: 10.1371/journal.pone.0046960] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Accepted: 09/07/2012] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Vacuolar (H(+))-ATPase (V-ATPase; V(1)V(o)-ATPase) is a large multisubunit enzyme complex found in the endomembrane system of all eukaryotic cells where its proton pumping action serves to acidify subcellular organelles. In the plasma membrane of certain specialized tissues, V-ATPase functions to pump protons from the cytoplasm into the extracellular space. The activity of the V-ATPase is regulated by a reversible dissociation mechanism that involves breaking and re-forming of protein-protein interactions in the V(1)-ATPase - V(o)-proton channel interface. The mechanism responsible for regulated V-ATPase dissociation is poorly understood, largely due to a lack of detailed knowledge of the molecular interactions that are responsible for the structural and functional link between the soluble ATPase and membrane bound proton channel domains. METHODOLOGY/PRINCIPAL FINDINGS To gain insight into where some of the stator subunits of the V-ATPase associate with each other, we have developed peptide arrays from the primary sequences of V-ATPase subunits. By probing the peptide arrays with individually expressed V-ATPase subunits, we have identified several key interactions involving stator subunits E, G, C, H and the N-terminal domain of the membrane bound a subunit. CONCLUSIONS The subunit-peptide interactions identified from the peptide arrays complement low resolution structural models of the eukaryotic vacuolar ATPase obtained from transmission electron microscopy. The subunit-subunit interaction data are discussed in context of our current model of reversible enzyme dissociation.
Collapse
Affiliation(s)
- Lee S. Parsons
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York, United States of America
| | - Stephan Wilkens
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York, United States of America
| |
Collapse
|