51
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Thudium CS, Moscatelli I, Löfvall H, Kertész Z, Montano C, Bjurström CF, Karsdal MA, Schulz A, Richter J, Henriksen K. Regulation and Function of Lentiviral Vector-Mediated TCIRG1 Expression in Osteoclasts from Patients with Infantile Malignant Osteopetrosis: Implications for Gene Therapy. Calcif Tissue Int 2016; 99:638-648. [PMID: 27541021 DOI: 10.1007/s00223-016-0187-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 08/08/2016] [Indexed: 10/21/2022]
Abstract
Infantile malignant osteopetrosis (IMO) is a rare, recessive disorder characterized by increased bone mass caused by dysfunctional osteoclasts. The disease is most often caused by mutations in the TCIRG1 gene encoding a subunit of the V-ATPase involved in the osteoclasts capacity to resorb bone. We previously showed that osteoclast function can be restored by lentiviral vector-mediated expression of TCIRG1, but the exact threshold for restoration of resorption as well as the cellular response to vector-mediated TCIRG1 expression is unknown. Here we show that expression of TCIRG1 protein from a bicistronic TCIRG1/GFP lentiviral vector was only observed in mature osteoclasts, and not in their precursors or macrophages, in contrast to GFP expression, which was observed under all conditions. Thus, vector-mediated TCIRG1 expression appears to be post-transcriptionally regulated, preventing overexpression and/or ectopic expression and ensuring protein expression similar to that of wild-type osteoclasts. Codon optimization of TCIRG1 led to increased expression of mRNA but lower levels of protein and functional rescue. When assessing the functional rescue threshold in vitro, addition of 30 % CB CD34+ cells to IMO CD34+ patient cells was sufficient to completely normalize resorptive function after osteoclast differentiation. From both an efficacy and a safety perspective, these findings will clearly be of benefit during further development of gene therapy for osteopetrosis.
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Affiliation(s)
| | - Ilana Moscatelli
- Department of Molecular Medicine and Gene Therapy, Lund Strategic Center for Stem Cell Biology, BMC A12, 221 84, Lund, Sweden
| | - Henrik Löfvall
- Nordic Bioscience, Herlev, Denmark
- Department of Molecular Medicine and Gene Therapy, Lund Strategic Center for Stem Cell Biology, BMC A12, 221 84, Lund, Sweden
| | - Zsuzsanna Kertész
- Department of Molecular Medicine and Gene Therapy, Lund Strategic Center for Stem Cell Biology, BMC A12, 221 84, Lund, Sweden
| | - Carmen Montano
- Department of Molecular Medicine and Gene Therapy, Lund Strategic Center for Stem Cell Biology, BMC A12, 221 84, Lund, Sweden
| | - Carmen Flores Bjurström
- Department of Molecular Medicine and Gene Therapy, Lund Strategic Center for Stem Cell Biology, BMC A12, 221 84, Lund, Sweden
| | | | - Ansgar Schulz
- Department of Pediatrics and Adolescent Medicine, University Medical Center, Ulm, Germany
| | - Johan Richter
- Department of Molecular Medicine and Gene Therapy, Lund Strategic Center for Stem Cell Biology, BMC A12, 221 84, Lund, Sweden.
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52
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Tekin M, Eruygur N. The structural studies on the medicinal plant Haplophyllum telephioides. REVISTA BRASILEIRA DE FARMACOGNOSIA 2016. [DOI: 10.1016/j.bjp.2016.05.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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53
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Wang Y, Xia C, Zhang W, Zhao Y. Synthesis and biological evaluation of novel lignan glycosides as anticancer agents. Chem Biol Drug Des 2016; 88:562-7. [DOI: 10.1111/cbdd.12785] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 04/09/2016] [Accepted: 04/25/2016] [Indexed: 12/28/2022]
Affiliation(s)
- Ying Wang
- School of Pharmacy; Nantong University; Nantong China
- Institute of Nautical Medicine; Nantong University; Nantong China
| | - Chao Xia
- School of Pharmacy; Nantong University; Nantong China
| | - Wei Zhang
- School of Pharmacy; Nantong University; Nantong China
| | - Yu Zhao
- School of Pharmacy; Nantong University; Nantong China
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54
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Lu Y, Zhang R, Liu S, Zhao Y, Gao J, Zhu L. ZT-25, a new vacuolar H(+)-ATPase inhibitor, induces apoptosis and protective autophagy through ROS generation in HepG2 cells. Eur J Pharmacol 2015; 771:130-8. [PMID: 26689625 DOI: 10.1016/j.ejphar.2015.12.026] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 12/06/2015] [Accepted: 12/11/2015] [Indexed: 12/29/2022]
Abstract
The vacuolar H(+)-ATPase (V-ATPase) has recently been proposed as a key target for new strategies in cancer treatment. Our previous work has proved that diphyllin glycoside is a novel inhibitor of V-ATPase. Here the cytotoxic effects of ZT-25, the most potent diphyllin glycoside derivatives, were studied and some of the underlying mechanisms were elucidated. ZT-25 displayed strong cytotoxicity on several cancer cell lines and relatively low cytotoxicity on human fetal hepatic cells (WRL-68) at submicromolar concentrations. In human hepatoma cells HepG2, ZT-25 induced G1/G0 phase arrest and apoptosis, as well as mitochondrial membrane potential (MMP) dissipation and ATP depletion. Furthermore, Bcl-2 protein decreased, while Bax protein and cleaved caspase-3 protein increased upon ZT-25 treatment. Benzyloxycarbony (Cbz)-l-Val-Ala-Asp (OMe)-fluoromethylketone (Z-VAD-FMK), a well-known pan-caspase inhibitor, attenuated ZT-25-induced cell death, suggesting the involvement of caspase-dependent pathway. Intriguingly, ZT-25 induced autophagy in HepG2 cells as characterized by increased the conversion of LC3 I to LC3 II, Beclin-1 expression and autophagosome formation. Meanwhile, p-mTOR expression was decreased which indicated that ZT-25-induced autophagy might be mediated through the suppression of mTOR pathway. Inhibition of autophagy by 3-methyladenine (3-MA) and chloroquine (CQ) obviously promoted ZT-25-induced cell death, suggesting the protective role of autophagy. Increased intracellular ROS level was found to be the early event in ZT-25-treated HepG2 cells. Inhibition of ROS generation by N-acetyl-l-cysteine (NAC) attenuated ZT-25-induced cell death and autophagy. Together, these results provide key insights into the ZT-25-induced cytotoxicity in HepG2 cells, which will have a great impact on the further development of diphyllin derivatives.
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Affiliation(s)
- Yapeng Lu
- School of Medicine, Jiangsu University, Zhenjiang 212013, China; Institute of Nautical Medicine, Nantong University, Nantong 226019, China
| | - Rui Zhang
- Department of Neurology, Deji Hospital, Shanghai 200331, China
| | - Siyuan Liu
- Institute of Nautical Medicine, Nantong University, Nantong 226019, China
| | - Yu Zhao
- Institute of Nautical Medicine, Nantong University, Nantong 226019, China
| | - Jing Gao
- School of Pharmacy, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013, China.
| | - Li Zhu
- Institute of Nautical Medicine, Nantong University, Nantong 226019, China.
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55
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Zhao Y, Zhang R, Lu Y, Ma J, Zhu L. Synthesis and bioevaluation of heterocyclic derivatives of Cleistanthin-A. Bioorg Med Chem 2015; 23:4884-4890. [DOI: 10.1016/j.bmc.2015.05.033] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 05/13/2015] [Accepted: 05/15/2015] [Indexed: 10/23/2022]
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56
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Naresh G, Kant R, Narender T. Silver(I)-Catalyzed Regioselective Construction of Highly Substituted α-Naphthols and Its Application toward Expeditious Synthesis of Lignan Natural Products. Org Lett 2015; 17:3446-9. [DOI: 10.1021/acs.orglett.5b01477] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Gunaganti Naresh
- Medicinal and Process Chemistry
Division and ‡Molecular and Structural Biology
Division, CSIR-Central Drug Research Institute, Lucknow 226031, India
| | - Ruchir Kant
- Medicinal and Process Chemistry
Division and ‡Molecular and Structural Biology
Division, CSIR-Central Drug Research Institute, Lucknow 226031, India
| | - Tadigoppula Narender
- Medicinal and Process Chemistry
Division and ‡Molecular and Structural Biology
Division, CSIR-Central Drug Research Institute, Lucknow 226031, India
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57
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Ying H, Qin A, Cheng TS, Pavlos NJ, Rea S, Dai K, Zheng MH. Disulfiram attenuates osteoclast differentiation in vitro: a potential antiresorptive agent. PLoS One 2015; 10:e0125696. [PMID: 25928135 PMCID: PMC4416043 DOI: 10.1371/journal.pone.0125696] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 03/19/2015] [Indexed: 01/08/2023] Open
Abstract
Disulfiram (DSF), a cysteine modifying compound, has long been clinically employed for the treatment of alcohol addiction. Mechanistically, DSF acts as a modulator of MAPK and NF-κB pathways signaling pathways. While these pathways are crucial for osteoclast (OC) differentiation, the potential influence of DSF on OC formation and function has not been directly assessed. Here, we explore the pharmacological effects of DSF on OC differentiation, activity and the modulation of osteoclastogenic signaling cascades. We first analyzed cytotoxicity of DSF on bone marrow monocytes isolated from C57BL/6J mice. Upon the establishment of optimal dosage, we conducted osteoclastogenesis and bone resorption assays in the presence or absence of DSF treatment. Luciferase assays in RAW264.7 cells were used to examine the effects of DSF on major transcription factors activation. Western blot, reverse transcription polymerase chain reaction, intracellular acidification and proton influx assays were employed to further dissect the underlying mechanism. DSF treatment dose-dependently inhibited both mouse and human osteoclastogenesis, especially at early stages of differentiation. This inhibition correlated with a decrease in the expression of key osteoclastic marker genes including CtsK, TRAP, DC-STAMP and Atp6v0d2 as well as a reduction in bone resorption in vitro. Suppression of OC differentiation was found to be due, at least in part, to the blockade of several key receptor activators of nuclear factor kappa-B ligand (RANKL)-signaling pathways including ERK, NF-κB and NFATc1. On the other hand, DSF failed to suppress intracellular acidification and proton influx in mouse and human osteoclasts using acridine orange quenching and microsome-based proton transport assays. Our findings indicate that DSF attenuates OC differentiation via the collective suppression of several key RANKL-mediated signaling cascades, thus making it an attractive agent for the treatment of OC-mediated disorders.
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Affiliation(s)
- Hua Ying
- Centre for Orthopaedic Research, School of Surgery, The University of Western Australia, Perth, Australia
| | - An Qin
- Centre for Orthopaedic Research, School of Surgery, The University of Western Australia, Perth, Australia
- Department of Orthopaedics, The Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Tak S. Cheng
- Centre for Orthopaedic Research, School of Surgery, The University of Western Australia, Perth, Australia
| | - Nathan J. Pavlos
- Centre for Orthopaedic Research, School of Surgery, The University of Western Australia, Perth, Australia
| | - Sarah Rea
- Harry Perkins Institute of Medical Research, Perth, Australia
- Department of Endocrinology & Diabetes, Sir Charles Gairdner Hospital, Perth, Australia
| | - Kerong Dai
- Department of Orthopaedics, The Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- * E-mail: (MHZ); (KD)
| | - Ming H. Zheng
- Centre for Orthopaedic Research, School of Surgery, The University of Western Australia, Perth, Australia
- * E-mail: (MHZ); (KD)
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58
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Zhao Y, Lu Y, Ma J, Zhu L. Synthesis and Evaluation of Cleistanthin A Derivatives as Potent Vacuolar H+-ATPase Inhibitors. Chem Biol Drug Des 2015; 86:691-6. [DOI: 10.1111/cbdd.12538] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Revised: 01/06/2015] [Accepted: 02/02/2015] [Indexed: 11/30/2022]
Affiliation(s)
- Yu Zhao
- Institute of Nautical Medicine; Nantong University; Nantong 226001 China
| | - Yapeng Lu
- Institute of Nautical Medicine; Nantong University; Nantong 226001 China
| | - Jinlong Ma
- Institute of Nautical Medicine; Nantong University; Nantong 226001 China
| | - Li Zhu
- Institute of Nautical Medicine; Nantong University; Nantong 226001 China
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59
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Das S, Hamide A, Mohanty MK, Muthusamy R. Fatal Cleistanthus collinus toxicity: a case report and review of literature. J Forensic Sci 2014; 59:1441-7. [PMID: 25040437 DOI: 10.1111/1556-4029.12519] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Revised: 05/31/2013] [Accepted: 08/24/2013] [Indexed: 11/29/2022]
Abstract
Cleistanthus collinus is an extremely toxic plant poison. We report a case of suicidal ingestion of boiled water decoction of C. collinus where the patient presented with abdominal pain and giddiness. There was persistent metabolic acidosis and fluctuation in the level of serum potassium. The ECG changes indicated a probable myocardial injury with conduction abnormality. At autopsy, the viscera were found to be congested. The toxins were detected in the viscera and blood by TLC and HPLC. Cleistanthin A and B, collinusin, and diphyllin are the principal toxic constituents of the plant. Consumption of a boiled decoction of leaves is highly toxic and, medical management of patients is mainly supportive because the molecular mechanisms of toxin action are unknown. In the recent years, C. collinus has created a considerable amount of interest because of its complex metabolites and their cytotoxic activities. Through this study, the authors have tried to highlight different properties pertaining to C. collinus.
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Affiliation(s)
- Siddhartha Das
- Department of Forensic Medicine & Toxicology, JIPMER, Puducherry, 605006, India
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60
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Zhang Z, Ma J, Zhu L, Zhao Y. Synthesis and identification of cytotoxic diphyllin glycosides as vacuolar H+-ATPase inhibitors. Eur J Med Chem 2014; 82:466-71. [DOI: 10.1016/j.ejmech.2014.06.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 05/26/2014] [Accepted: 06/01/2014] [Indexed: 02/07/2023]
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61
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Moscatelli I, Thudium CS, Flores C, Schulz A, Askmyr M, Gudmann NS, Andersen NM, Porras O, Karsdal MA, Villa A, Fasth A, Henriksen K, Richter J. Lentiviral gene transfer of TCIRG1 into peripheral blood CD34(+) cells restores osteoclast function in infantile malignant osteopetrosis. Bone 2013; 57:1-9. [PMID: 23907031 DOI: 10.1016/j.bone.2013.07.026] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Revised: 06/12/2013] [Accepted: 07/17/2013] [Indexed: 12/22/2022]
Abstract
Infantile malignant osteopetrosis (IMO) is a rare, lethal, autosomal recessive disorder characterized by non-functional osteoclasts. More than 50% of the patients have mutations in the TCIRG1 gene, encoding for a subunit of the osteoclast proton pump. The aim of this study was to restore the resorptive function of IMO osteoclasts by lentiviral mediated gene transfer of the TCIRG1 cDNA. CD34(+) cells from peripheral blood of five IMO patients and from normal cord blood were transduced with lentiviral vectors expressing TCIRG1 and GFP under a SFFV promoter, expanded in culture and differentiated on bone slices to mature osteoclasts. qPCR analysis and western blot revealed increased mRNA and protein levels of TCIRG1, comparable to controls. Vector corrected IMO osteoclasts generated increased release of Ca(2+) and bone degradation product CTX-I into the media as well as increased formation of resorption pits in the bone slices, while non-corrected IMO osteoclasts failed to resorb bone. Resorption was approximately 70-80% of that of osteoclasts generated from cord blood. Furthermore, transduced CD34(+) cells successfully engrafted in NSG-mice. In conclusion we provide the first evidence of lentiviral-mediated correction of a human genetic disease affecting the osteoclastic lineage.
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Affiliation(s)
- Ilana Moscatelli
- Department of Molecular Medicine and Gene Therapy, Lund Strategic Center for Stem Cell Biology, Lund, Sweden
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62
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Kim SH, Moon SH. Osteoclast differentiation inhibitors: a patent review (2008 – 2012). Expert Opin Ther Pat 2013; 23:1591-610. [DOI: 10.1517/13543776.2013.842556] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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63
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Kallifatidis G, Hoepfner D, Jaeg T, Guzmán EA, Wright AE. The marine natural product manzamine A targets vacuolar ATPases and inhibits autophagy in pancreatic cancer cells. Mar Drugs 2013; 11:3500-16. [PMID: 24048269 PMCID: PMC3806460 DOI: 10.3390/md11093500] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 08/31/2013] [Accepted: 09/03/2013] [Indexed: 01/02/2023] Open
Abstract
Manzamine A, a member of the manzamine alkaloids, was originally isolated from marine sponges of the genus Haliclona. It was recently shown to have activity against pancreatic cancer cells, but the precise mechanism of action remained unclear. To further our understanding of the mechanism of action of manzamine A, chemogenomic profiling in the yeast S. cerevisiae was performed, suggesting that manzamine A is an uncoupler of vacuolar ATPases. Fluorescence microscopy confirmed this effect on yeast vacuoles, where manzamine A produced a phenotype very similar to that of the established v-ATPase inhibitor bafilomycin A1. In pancreatic cancer cells, 10 µM manzamine A affected vacuolar ATPase activity and significantly increased the level of autophagosome marker LC3-II and p62/SQSTM1 as observed by western blot analysis. Treatment with manzamine A in combination with bafilomycin A1 (inhibitor of autophagosome-lysosome fusion) did not change the levels of LC3-II when compared to cells treated with bafilomycin A1 alone, suggesting that manzamine A is a potential inhibitor of autophagy by preventing autophagosome turnover. As autophagy is essential for pancreatic tumor growth, blocking this pathway with manzamine A suggests a promising strategy for the treatment of pancreatic cancer.
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Affiliation(s)
- Georgios Kallifatidis
- Marine Biomedical and Biotechnology Research Program, Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 North, Fort Pierce, FL 34946, USA; E-Mails: (G.K.); (A.E.W.)
| | - Dominic Hoepfner
- Novartis Institutes for BioMedical Research, Developmental & Molecular Pathways, Novartis Pharma AG, WSJ-355.1.051.21, Fabrikstrasse 22, Basel CH-4056, Switzerland; E-Mails: (D.H.); (T.J.)
| | - Tiphaine Jaeg
- Novartis Institutes for BioMedical Research, Developmental & Molecular Pathways, Novartis Pharma AG, WSJ-355.1.051.21, Fabrikstrasse 22, Basel CH-4056, Switzerland; E-Mails: (D.H.); (T.J.)
| | - Esther A. Guzmán
- Marine Biomedical and Biotechnology Research Program, Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 North, Fort Pierce, FL 34946, USA; E-Mails: (G.K.); (A.E.W.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-772-242-2452; Fax: +1-772-242-2332
| | - Amy E. Wright
- Marine Biomedical and Biotechnology Research Program, Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 North, Fort Pierce, FL 34946, USA; E-Mails: (G.K.); (A.E.W.)
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64
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Chrispal A. Cleistanthus collinus poisoning. J Emerg Trauma Shock 2013; 5:160-6. [PMID: 22787347 PMCID: PMC3391841 DOI: 10.4103/0974-2700.96486] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2011] [Accepted: 01/10/2011] [Indexed: 11/17/2022] Open
Abstract
Cleistanthus collinus, a toxic shrub, is used for deliberate self-harm in rural South India. MEDLINE (PUBMED) and Google were searched for published papers using the search/ MeSH terms “Cleistanthus collinus,” “Euphorbiaceae,” “Diphyllin,” “Cleistanthin A,” Cleistanthin B” and “Oduvanthalai.” Non-indexed journals and abstracts were searched by tracing citations in published papers. The toxic principles in the leaf include arylnaphthalene lignan lactones — Diphyllin and its glycoside derivatives Cleistanthin A and B. Toxin effect in animal models demonstrate neuromuscular blockade with muscle weakness, distal renal tubular acidosis (dRTA) and type 2 respiratory failure with conflicting evidence of cardiac involvement. Studies suggest a likely inhibition of thiol/thiol enzymes by the lignan-lactones, depletion of glutathione and ATPases in tissues. V-type H+ ATPase inhibition in the renal tubule has been demonstrated. Mortality occurs in up to 40% of C. collinus poisonings. Human toxicity results in renal tubular dysfunction, commonly dRTA, with resultant hypokalemia and normal anion gap metabolic acidosis. Aggressive management of these metabolic derangements is crucial. Acute respiratory distress syndrome (ARDS) is seen in severe cases. Cardiac rhythm abnormalities have been demonstrated in a number of clinical studies, though the role of temporary cardiac pacemakers in reducing mortality is uncertain. Consumption of decoctions of C. collinus leaves, hypokalemia, renal failure, severe metabolic acidosis, ARDS and cardiac arrhythmias occur in severe poisonings and predict mortality. Further study is essential to delineate mechanisms of organ injury and interventions, including antidotes, which will reduce mortality.
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Affiliation(s)
- Anugrah Chrispal
- Department of Medicine, Unit 2, Christian Medical College, Vellore, Tamil Nadu, India
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65
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Chen HW, Cheng JX, Liu MT, King K, Peng JY, Zhang XQ, Wang CH, Shresta S, Schooley RT, Liu YT. Inhibitory and combinatorial effect of diphyllin, a v-ATPase blocker, on influenza viruses. Antiviral Res 2013; 99:371-82. [PMID: 23820269 PMCID: PMC3787953 DOI: 10.1016/j.antiviral.2013.06.014] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Revised: 06/18/2013] [Accepted: 06/21/2013] [Indexed: 01/05/2023]
Abstract
Diphyllin inhibits endosomal acidification in MDCK cells and A549 cells. Treatment with diphyllin alters the cellular susceptibility to the influenza virus. Diphyllin demonstrated a broad-spectrum antiviral activity. The combination of diphyllin and other drugs showed an enhanced antiviral effect.
An influenza pandemic poses a serious threat to humans and animals. Conventional treatments against influenza include two classes of pathogen-targeting antivirals: M2 ion channel blockers (such as amantadine) and neuraminidase inhibitors (such as oseltamivir). Examination of the mechanism of influenza viral infection has shown that endosomal acidification plays a major role in facilitating the fusion between viral and endosomal membranes. This pathway has led to investigations on vacuolar ATPase (v-ATPase) activity, whose role as a regulating factor on influenza virus replication has been verified in extensive genome-wide screenings. Blocking v-ATPase activity thus presents the opportunity to interfere with influenza viral infection by preventing the pH-dependent membrane fusion between endosomes and virions. This study aims to apply diphyllin, a natural compound shown to be as a novel v-ATPase inhibitor, as a potential antiviral for various influenza virus strains using cell-based assays. The results show that diphyllin alters cellular susceptibility to influenza viruses through the inhibition of endosomal acidification, thus interfering with downstream virus replication, including that of known drug-resistant strains. In addition, combinatorial treatment of the host-targeting diphyllin with pathogen-targeting therapeutics (oseltamivir and amantadine) demonstrates enhanced antiviral effects and cell protection in vitro.
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Affiliation(s)
- Hui-Wen Chen
- Division of Infectious Disease, School of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, United Sates; Division of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, 9420 Athena Circle, La Jolla, CA 92037, United States; School of Veterinary Medicine, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
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66
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Bogum J, Faust D, Zühlke K, Eichhorst J, Moutty MC, Furkert J, Eldahshan A, Neuenschwander M, von Kries JP, Wiesner B, Trimpert C, Deen PMT, Valenti G, Rosenthal W, Klussmann E. Small-molecule screening identifies modulators of aquaporin-2 trafficking. J Am Soc Nephrol 2013; 24:744-58. [PMID: 23559583 DOI: 10.1681/asn.2012030295] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
In the principal cells of the renal collecting duct, arginine vasopressin (AVP) stimulates the synthesis of cAMP, leading to signaling events that culminate in the phosphorylation of aquaporin-2 water channels and their redistribution from intracellular domains to the plasma membrane via vesicular trafficking. The molecular mechanisms that control aquaporin-2 trafficking and the consequent water reabsorption, however, are not completely understood. Here, we used a cell-based assay and automated immunofluorescence microscopy to screen 17,700 small molecules for inhibitors of the cAMP-dependent redistribution of aquaporin-2. This approach identified 17 inhibitors, including 4-acetyldiphyllin, a selective blocker of vacuolar H(+)-ATPase that increases the pH of intracellular vesicles and causes accumulation of aquaporin-2 in the Golgi compartment. Although 4-acetyldiphyllin did not inhibit forskolin-induced increases in cAMP formation and downstream activation of protein kinase A (PKA), it did prevent cAMP/PKA-dependent phosphorylation at serine 256 of aquaporin-2, which triggers the redistribution to the plasma membrane. It did not, however, prevent cAMP-induced changes to the phosphorylation status at serines 261 or 269. Last, we identified the fungicide fluconazole as an inhibitor of cAMP-mediated redistribution of aquaporin-2, but its target in this pathway remains unknown. In conclusion, our screening approach provides a method to begin dissecting molecular mechanisms underlying AVP-mediated water reabsorption, evidenced by our identification of 4-acetyldiphyllin as a modulator of aquaporin-2 trafficking.
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Affiliation(s)
- Jana Bogum
- Max Delbrueck Center for Molecular Medicine, Robert-Rössle Strasse, 10 D-13125, Berlin, Germany
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67
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Henriksen K, Andreassen KV, Thudium CS, Gudmann KNS, Moscatelli I, Crüger-Hansen CE, Schulz AS, Dziegiel MH, Richter J, Karsdal MA, Neutzsky-Wulff AV. A specific subtype of osteoclasts secretes factors inducing nodule formation by osteoblasts. Bone 2012; 51:353-61. [PMID: 22722081 DOI: 10.1016/j.bone.2012.06.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 06/07/2012] [Accepted: 06/09/2012] [Indexed: 12/19/2022]
Abstract
Osteoclasts are known to be important for the coupling process between bone resorption and formation. The aim of this study was to address when osteoclasts are anabolically active. Human monocytes were differentiated into mature osteoclasts by treatment with M-CSF and RANKL. Conditioned medium was collected from macrophages, pre-osteoclasts, and mature functional or non-resorbing osteopetrotic osteoclasts on either bone, plastic, decalcified bone or dentine with or without diphyllin, E64 or GM6001. Osteoclasts numbers were measured by TRACP activity. Bone resorption was evaluated by CTX-I and calcium release. The osteoblastic cell line 2T3 was treated with 50% of CM or non-CM for 12days. Bone formation was assessed by Alizarin Red extraction. CM from mature osteoclasts induced bone formation, while CM from macrophages did not. Non-resorbing osteoclasts generated from osteopetrosis patients showed little resorption, but still an induction of bone formation by osteoblasts. Mimicking the reduction in bone resorption using the V-ATPase inhibitor Diphyllin, the cysteine proteinase inhibitor E64 and the MMP-inhibitor GM6001 showed that CM from diphyllin and E64 treated osteoclasts showed reduced ability to induce bone formation compared to CM from vehicle treated osteoclasts, while CM from GM6001 treated osteoclasts equaled vehicle CM. Osteoclasts on either dentine or decalcified bone showed strongly attenuated anabolic capacities. In conclusion, we present evidence that osteoclasts, both dependent and independent of their resorptive activity, secrete factors stimulating osteoblastic bone formation.
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Affiliation(s)
- Kim Henriksen
- Nordic Bioscience A/S, Bone Biology and Biomarkers, Herlev, Denmark.
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68
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Kim JL, Kang MK, Gong JH, Park SH, Han SY, Kang YH. Novel antiosteoclastogenic activity of phloretin antagonizing RANKL-induced osteoclast differentiation of murine macrophages. Mol Nutr Food Res 2012; 56:1223-33. [PMID: 22700286 DOI: 10.1002/mnfr.201100831] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2011] [Revised: 04/01/2012] [Accepted: 04/13/2012] [Indexed: 11/10/2022]
Abstract
SCOPE Bone-remodeling imbalance resulting in more bone resorption than bone formation is known to cause skeletal diseases such as osteoporosis. Phloretin, a natural dihydrochalcone compound largely present in apple peels, possesses antiphotoaging, and antiinflammatory activity. METHODS AND RESULTS Phloretin inhibited receptor activator of NF-κB ligand (RANKL)-induced formation of multinucleated osteoclasts and diminished bone resorption area produced during the osteoclast differentiation process. It was also found that ≥ 10 μM phloretin reduced RANKL-enhanced tartrate-resistance acid phosphatase activity and matrix metalloproteinase-9 secretion in a dose-dependent manner. The phloretin treatment retarded RANKL-induced expression of carbonic anhydrase II, vacuolar-type H(+) -ATPase D2 and β3 integrin, all involved in the bone resorption. Furthermore, submicromolar phloretin diminished the expression and secretion of cathepsin K elevated by RANKL, being concurrent with inhibition of TRAF6 induction and NF-κB activation. RANKL-induced activation of nuclear factor of activated T cells c1 (NFATc1) and microphthalmia-associated transcription factor was also suppressed by phloretin. CONCLUSION These results demonstrate that the inhibition of osteoclast differentiation and bone resorption by phloretin entail a disturbance of TRAF6-NFATc1-NF-κB pathway triggered by RANKL. Therefore, phloretin may be a potential therapeutic agent targeting osteoclast differentiation and bone resorption in skeletal diseases such as osteoporosis.
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Affiliation(s)
- Jung-Lye Kim
- Department of Food Science and Nutrition, Hallym University, Chuncheon, Korea
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69
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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.
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Affiliation(s)
- A Qin
- Centre for Orthopaedic Research, School of Surgery, The University of Western Australia, Crawley, Australia.
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70
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Henriksen K, Karsdal MA, Taylor A, Tosh D, Coxon FP. Generation of human osteoclasts from peripheral blood. Methods Mol Biol 2012; 816:159-75. [PMID: 22130928 DOI: 10.1007/978-1-61779-415-5_11] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Osteoclasts are multi-nucleated cells that have the unique ability to resorb calcified bone matrix. They derive from haematopoietic precursor cells, and can be generated in vitro by stimulation of peripheral blood mononuclear cells with the cytokines M-CSF and RANKL. In this chapter, we describe the method for generating human osteoclast from peripheral blood or buffy coats, as well as methods for studying both the differentiation and resorbing activity of these cells.
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71
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Henriksen K, Flores C, Thomsen JS, Brüel AM, Thudium CS, Neutzsky-Wulff AV, Langenbach GEJ, Sims N, Askmyr M, Martin TJ, Everts V, Karsdal MA, Richter J. Dissociation of bone resorption and bone formation in adult mice with a non-functional V-ATPase in osteoclasts leads to increased bone strength. PLoS One 2011; 6:e27482. [PMID: 22087326 PMCID: PMC3210177 DOI: 10.1371/journal.pone.0027482] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Accepted: 10/17/2011] [Indexed: 01/23/2023] Open
Abstract
Osteopetrosis caused by defective acid secretion by the osteoclast, is characterized by defective bone resorption, increased osteoclast numbers, while bone formation is normal or increased. In contrast the bones are of poor quality, despite this uncoupling of formation from resorption.To shed light on the effect of uncoupling in adult mice with respect to bone strength, we transplanted irradiated three-month old normal mice with hematopoietic stem cells from control or oc/oc mice, which have defective acid secretion, and followed them for 12 to 28 weeks.Engraftment levels were assessed by flow cytometry of peripheral blood. Serum samples were collected every six weeks for measurement of bone turnover markers. At termination bones were collected for µCT and mechanical testing. An engraftment level of 98% was obtained. From week 6 until termination bone resorption was significantly reduced, while the osteoclast number was increased when comparing oc/oc to controls. Bone formation was elevated at week 6, normalized at week 12, and reduced onwards. µCT and mechanical analyses of femurs and vertebrae showed increased bone volume and bone strength of cortical and trabecular bone.In conclusion, these data show that attenuation of acid secretion in adult mice leads to uncoupling and improves bone strength.
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72
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Liu BL, Tzeng YM. Development and applications of destruxins: a review. Biotechnol Adv 2011; 30:1242-54. [PMID: 22079799 DOI: 10.1016/j.biotechadv.2011.10.006] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Revised: 10/24/2011] [Accepted: 10/24/2011] [Indexed: 01/13/2023]
Abstract
The insecticidal and phytotoxic activities of destruxins (dtxs) have been well studied. The cyclodepsipeptides, which are dtxs mainly isolated from the fungus Metarhizium anisopliae and other fungi, have been well characterized in vitro and in vivo. A succession of important function, such as antitumoral, antiviral, insecticidal, cytotoxic, immunosuppressant, phytotoxic, and antiproliferative effects have been observed. To date, 39 dtxs derivatives have been identified. Dtxs possess a variety of biological activities, including acting as virulence factors for specific insects, a V-ATPase inhibitor that provides a basis for the development of new drug to against osteoporosis, cancer, or biological control agents, etc. Here, we focus on some of the research progress made on understanding dtxs during the last decade, introduce some of the newly identified dtx members, especially from M. anisopliae, and give an overview of the applications of dtxs. Using the dtxs to learn about and moderate biological events has advanced significantly during the past year. We believe that several ongoing dtx application fields may benefit from the reviewed information herein.
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Affiliation(s)
- Bing-Lan Liu
- Department of Applied Chemistry, Chaoyang University of Technology, Taichung 41349, Taiwan
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73
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Knight AJ, Behm CA. Minireview: the role of the vacuolar ATPase in nematodes. Exp Parasitol 2011; 132:47-55. [PMID: 21959022 DOI: 10.1016/j.exppara.2011.09.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Revised: 09/08/2011] [Accepted: 09/13/2011] [Indexed: 11/28/2022]
Abstract
The vacuolar ATPase enzyme complex (V-ATPase) pumps protons across membranes, energised by hydrolysis of ATP. It is involved in many physiological processes and has been implicated in many different diseases. While the broader functions of V-ATPases have been reviewed extensively, the role of this complex in nematodes specifically has not. Here, the essential role of the V-ATPase in nematode nutrition, osmoregulation, synthesis of the cuticle, neurobiology and reproduction is discussed. Based on the requirement of V-ATPase activity, or components of the V-ATPase, for these processes, the potential of the V-ATPase as a drug target for nematode parasites, which cause a significant burden to human health and agriculture, is also discussed. The V-ATPase has all the characteristics of a suitable drug target against nematodes, however the challenge will be to develop a high-throughput assay with which to test potential inhibitors.
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Affiliation(s)
- Alison J Knight
- Research School of Biology, College of Medicine, Biology and Environment, Australian National University, Canberra ACT 0200, Australia
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74
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Kettimuthu KP, Lourthuraj AA, Manickam AS, Subramani S, Ramachandran A. Mechanisms of toxicity of Cleistanthus collinus: vacuolar ATPases are a putative target. Clin Toxicol (Phila) 2011; 49:457-63. [PMID: 21824057 DOI: 10.3109/15563650.2011.590939] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Ingestion of Cleistanthus collinus, a shrub native to South India, either intentionally or accidentally, is a common cause of death in the area. Consumption of a boiled decoction of leaves is highly toxic, but medical management of patients is mainly supportive because the molecular mechanisms of toxin action are unknown. Distal renal tubular acidosis is one of the symptoms of poisoning in patients and adenosine triphosphate (ATP) requiring proton pumps is important for acid secretion in the kidney. Hence, we hypothesized that these may be putative targets for C. collinus action and we tested this by exposing rat renal brush border membrane (BBM) as well as cultured kidney cells to a boiled decoction of C. collinus. Exposure to the C. collinus decoction resulted in significant inhibition of vacuolar type H(+)-ATPase (V-ATPase) activity in renal BBM as well as blocking of the proton pump in renal BBM vesicles. C. collinus decoction was also found to inhibit acidification of intracellular organelles in cells in culture, similar to the effect seen with either bafilomycin or concanamycin - specific inhibitors of the V-ATPase. This was accompanied by a decrease in V-ATPase activity, but an increase in protein levels. These results demonstrate that the V-ATPase in renal cells is a putative target for the toxins in C. collinus and the inhibition of this important proton pump probably plays a role in the development of distal renal tubular acidosis and subsequent renal failure seen in poisoned patients.
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Affiliation(s)
- Kavitha Priya Kettimuthu
- The Wellcome Trust Research Laboratory, Department of Gastrointestinal Sciences, Christian Medical College, Vellore, India
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75
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Abstract
Standard surgical approaches for Perthes disease consist of nonoperative physical treatments or surgical treatment. Several investigators have been working on a better understanding of the pathophysiology and pathobiology of Perthes disease. Most of the focus has been on antiresorptive treatments. Other treatment avenues, however, include controlling the inflammatory phase of Perthes disease, increasing revascularization of necrotic bone, and anabolic strategies to increase bone formation. This article presents a current pathophysiological model of Perthes disease, reviews experimental strategies in pharmaceutical treatments, and suggests future areas for research.
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Affiliation(s)
- David G Little
- Department of Orthopaedics, Orthopaedic Research, The Children's Hospital at Westmead, Westmead, NSW, Australia.
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76
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Shen W, Zou X, Chen M, Liu P, Shen Y, Huang S, Guo H, Zhang L. Effects of diphyllin as a novel V-ATPase inhibitor on gastric adenocarcinoma. Eur J Pharmacol 2011; 667:330-8. [PMID: 21645513 DOI: 10.1016/j.ejphar.2011.05.042] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2010] [Revised: 05/16/2011] [Accepted: 05/22/2011] [Indexed: 02/06/2023]
Abstract
The natural compound diphyllin, a cytostatic lignan isolated from Cleistanthus collinus, can dramatically inhibit the proliferation and induce the apoptosis of human gastric cancer cells, SGC7901. Our study found that diphyllin can inhibit the expression of V-ATPases in a dose-dependent manner, decrease the internal pH (pHi) and reverse the transmembrane pH gradient in SGC7901 cells. Changes of the pH gradient were positively correlated with diphyllin concentration. Further study found that diphyllin treatment caused a decrease in phospho-LRP6, but not in LRP6. β-catenin in Wnt/β-catenin signaling and its target genes, c-myc and cyclin-D1, were also decreased with the inhibition of V-ATPases. Therefore, diphyllin could be characterized as a new V-ATPase inhibitor in treating gastric cancer and inhibiting the phosphorylation of LRP6 in Wnt/β-catenin signaling.
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Affiliation(s)
- Weidong Shen
- Department of Gastroenterology, Nanjing Drum Tower Hospital Clinical College of Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210008, PR China
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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.
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Affiliation(s)
- Binyun Ma
- Key Laboratory of Arid and Grassland Agroecology of Ministry of Education, School of Life Sciences, Lanzhou University, 730000, Lanzhou, China
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Henriksen K, Bollerslev J, Everts V, Karsdal MA. Osteoclast activity and subtypes as a function of physiology and pathology--implications for future treatments of osteoporosis. Endocr Rev 2011; 32:31-63. [PMID: 20851921 DOI: 10.1210/er.2010-0006] [Citation(s) in RCA: 157] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Osteoclasts have traditionally been associated exclusively with catabolic functions that are a prerequisite for bone resorption. However, emerging data suggest that osteoclasts also carry out functions that are important for optimal bone formation and bone quality. Moreover, recent findings indicate that osteoclasts have different subtypes depending on their location, genotype, and possibly in response to drug intervention. The aim of the current review is to describe the subtypes of osteoclasts in four different settings: 1) physiological, in relation to turnover of different bone types; 2) pathological, as exemplified by monogenomic disorders; 3) pathological, as identified by different disorders; and 4) in drug-induced situations. The profiles of these subtypes strongly suggest that these osteoclasts belong to a heterogeneous cell population, namely, a diverse macrophage-associated cell type with bone catabolic and anabolic functions that are dependent on both local and systemic parameters. Further insight into these osteoclast subtypes may be important for understanding cell-cell communication in the bone microenvironment, treatment effects, and ultimately bone quality.
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Affiliation(s)
- K Henriksen
- Nordic Bioscience A/S, Herlev Hovedgade 207, DK-2730 Herlev, Denmark.
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Jensen VK, Nosjean O, Dziegiel MH, Boutin JA, Sørensen MG, Karsdal MA, Henriksen K. A quantitative assay for lysosomal acidification rates in human osteoclasts. Assay Drug Dev Technol 2010; 9:157-64. [PMID: 21050068 DOI: 10.1089/adt.2010.0272] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The osteoclast initiates resorption by creating a resorption lacuna. The ruffled border surrounding the lacunae arises from exocytosis of lysosomes. To dissolve the inorganic phase of the bone, the vacuolar adenosine triphosphatase, located in the ruffled border, pumps protons into the resorption lacunae. The electroneutrality of the lacunae is maintained by chloride transport through the chloride-proton antiporter chloride channel 7. Inhibition of either proton or chloride transport prevents bone resorption. The aims of this study were to validate the human osteoclastic microsome- based influx assay with respect to lysosomal acidification and assess whether it is a reliable test of a compound's ability to inhibit acidification. Investigated were the expression levels of the lysosomal acidification machinery, the activation of the assay by adenosine triphosphate, H(+) and Cl(-) dependency, the effect of valinomycin, inhibitor sensitivity, and the ion profile of the human osteoclast microsomes. The expression level of chloride channel 7 was increased in the human osteoclastic microsomes compared with whole osteoclasts. Acid influx was induced by 1.25 mM adenosine triphosphate. Further 1.1 μM valinomycin increased the acid influx by 129%. Total abrogation of acid influx was observed using both H(+) and Cl(-) ionophores. Finally, investigation of the anion profile demonstrated that Cl(-) and Br(-) are the preferred anions for the transporter. In conclusion, the acid influx assay based on microsomes from human osteoclasts is a useful tool for detection of inhibitors of the osteoclastic acidification machinery, and thus may aid the identification of effective drugs for osteoporosis that target the acid secretion by osteoclasts.
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Sørensen MG, Karsdal MA, Dziegiel MH, Boutin JA, Nosjean O, Henriksen K. Screening of protein kinase inhibitors identifies PKC inhibitors as inhibitors of osteoclastic acid secretion and bone resorption. BMC Musculoskelet Disord 2010; 11:250. [PMID: 20977756 PMCID: PMC2978137 DOI: 10.1186/1471-2474-11-250] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2009] [Accepted: 10/26/2010] [Indexed: 01/08/2023] Open
Abstract
Background Bone resorption is initiated by osteoclastic acidification of the resorption lacunae. This process is mediated by secretion of protons through the V-ATPase and chloride through the chloride antiporter ClC-7. To shed light on the intracellular signalling controlling extracellular acidification, we screened a protein kinase inhibitor library in human osteoclasts. Methods Human osteoclasts were generated from CD14+ monocytes. The effect of different kinase inhibitors on lysosomal acidification in human osteoclasts was investigated using acridine orange for different incubation times (45 minutes, 4 and 24 hours). The inhibitors were tested in an acid influx assay using microsomes isolated from human osteoclasts. Bone resorption by human osteoclasts on bone slices was measured by calcium release. Cell viability was measured using AlamarBlue. Results Of the 51 compounds investigated only few inhibitors were positive in both acidification and resorption assays. Rottlerin, GF109203X, Hypericin and Ro31-8220 inhibited acid influx in microsomes and bone resorption, while Sphingosine and Palmitoyl-DL-carnitine-Cl showed low levels of inhibition. Rottlerin inhibited lysosomal acidification in human osteoclasts potently. Conclusions In conclusion, a group of inhibitors all indicated to inhibit PKC reduced acidification in human osteoclasts, and thereby bone resorption, indicating that acid secretion by osteoclasts may be specifically regulated by PKC in osteoclasts.
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81
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Maneksh D, Sidharthan A, Kettimuthu K, Kanthakumar P, Lourthuraj AA, Ramachandran A, Subramani S. Cleistanthus collinus induces type I distal renal tubular acidosis and type II respiratory failure in rats. Indian J Pharmacol 2010; 42:178-84. [PMID: 20871771 PMCID: PMC2937321 DOI: 10.4103/0253-7613.66843] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2010] [Revised: 05/19/2010] [Accepted: 06/09/2010] [Indexed: 11/08/2022] Open
Abstract
Background and Purpose: A water decoction of the poisonous shrub Cleistanthus collinus is used for suicidal purposes. The mortality rate is 28%. The clinical profile includes distal renal tubular acidosis (DRTA) and respiratory failure. The mechanism of toxicity is unclear. Objectives: To demonstrate features of C. collinus toxicity in a rat model and to identify its mechanism(s) of action. Materials and Methods: Rats were anesthetized and the carotid artery was cannulated. Electrocardiogram and respiratory movements were recorded. Either aqueous extract of C. collinus or control solution was administered intraperitoneally. Serial measurements of blood gases, electrolytes and urinary pH were made. Isolated brush border and basolateral membranes from rat kidney were incubated with C. collinus extract and reduction in ATPase activity was assessed. Venous blood samples from human volunteers and rats were incubated with an acetone extract of C. collinus and plasma potassium was estimated as an assay for sodium–potassium pump activity. Results: The mortality was 100% in tests and 17% in controls. Terminal event in test animals was respiratory arrest. Controls had metabolic acidosis, respiratory compensation acidic urine and hyperkalemia. Test animals showed respiratory acidosis, alkaline urine and low blood potassium as compared to controls. C. collinus extract inhibited ATPase activity in rat kidney. Plasma K+ did not increase in human blood incubated with C. collinus extract. Conclusions and Implications: Active principles of C. collinus inhibit proton pumps in the renal brush border, resulting in type I DRTA in rats. There is no inhibition of sodium–potassium pump activity. Test animals develop respiratory acidosis, and the immediate cause of death is respiratory arrest.
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Affiliation(s)
- Delinda Maneksh
- Department of Physiology, Dr. Somervell Memorial C.S.I. Medical College and Hospital, Karakonam, Kerala, India
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Alterations in osteoclast function and phenotype induced by different inhibitors of bone resorption--implications for osteoclast quality. BMC Musculoskelet Disord 2010; 11:109. [PMID: 20515459 PMCID: PMC2891608 DOI: 10.1186/1471-2474-11-109] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2009] [Accepted: 06/01/2010] [Indexed: 01/23/2023] Open
Abstract
Background Normal osteoclasts resorb bone by secretion of acid and proteases. Recent studies of patients with loss of function mutations affecting either of these processes have indicated a divergence in osteoclastic phenotypes. These difference in osteoclast phenotypes may directly or indirectly have secondary effects on bone remodeling, a process which is of importance for the pathogenesis of both osteoporosis and osteoarthritis. We treated human osteoclasts with different inhibitors and characterized their resulting function. Methods Human CD14 + monocytes were differentiated into mature osteoclasts using RANKL and M-CSF. The osteoclasts were cultured on bone in the presence or absence of various inhibitors: Inhibitors of acidification (bafilomycin A1, diphyllin, ethoxyzolamide), inhibitors of proteolysis (E64, GM6001), or a bisphosphonate (ibandronate). Osteoclast numbers and bone resorption were monitored by measurements of TRACP activity, the release of calcium, CTX-I and ICTP, as well as by counting resorption pits. Results All inhibitors of acidification were equally potent with respect to inhibition of both organic and inorganic resorption. In contrast, inhibition of proteolysis by E64 potently reduced organic resorption, but only modestly suppressed inorganic resorption. GM6001 alone did not greatly affect bone resorption. However, when GM6001 and E64 were combined, a complete abrogation of organic bone resorption was observed, without a great effect on inorganic resorption. Ibandronate abrogated both organic and inorganic resorption at all concentrations tested [0.3-100 μM], however, this treatment dramatically reduced TRACP activity. Conclusions We present evidence highlighting important differences with respect to osteoclast function, when comparing the different types of osteoclast inhibitors. Each class of osteoclast inhibitors will lead to different alterations in osteoclast quality, which secondarily may lead to different bone qualities.
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83
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Barascuk N, Skjøt-Arkil H, Register TC, Larsen L, Byrjalsen I, Christiansen C, Karsdal MA. Human macrophage foam cells degrade atherosclerotic plaques through cathepsin K mediated processes. BMC Cardiovasc Disord 2010; 10:19. [PMID: 20409295 PMCID: PMC2868786 DOI: 10.1186/1471-2261-10-19] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2009] [Accepted: 04/21/2010] [Indexed: 11/27/2022] Open
Abstract
Background Proteolytic degradation of Type I Collagen by proteases may play an important role in remodeling of atherosclerotic plaques, contributing to increased risk of plaque rupture. The aim of the current study was to investigate whether human macrophage foam cells degrade the extracellular matrix (ECM) of atherosclerotic plaques by cathepsin K mediated processes. Methods We 1) cultured human macrophages on ECM and measured cathepsin K generated fragments of type I collagen (C-terminal fragments of Type I collagen (CTX-I) 2) investigated the presence of CTX-I in human coronary arteries and 3) finally investigated the clinical potential by measuring circulating CTX-I in women with and without radiographic evidence of aortic calcified atherosclerosis. Results Immune-histochemistry of early and advanced lesions of coronary arteries demonstrated co-localization of Cathepsin-K and CTX-I in areas of intimal hyperplasia and in shoulder regions of advanced plaques. Treatment of human monocytes with M-CSF or M-CSF+LDL generated macrophages and foam cells producing CTX-I when cultured on type I collagen enriched matrix. Circulating levels of CTX-I were not significantly different in women with aortic calcifications compared to those without. Conclusions Human macrophage foam cells degrade the atherosclerotic plaques though cathepsin K mediated processes, resulting in increase in levels of CTX-I. Serum CTX-I was not elevated in women with aortic calcification, likely due to the contribution of CTX-I from osteoclastic bone resorption which involves Cathepsin-K. The human macrophage model system may be used to identify important pathway leading to excessive proteolytic plaque remodeling and plaque rupture.
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The vacuolar ATPase in bone cells: a potential therapeutic target in osteoporosis. Mol Biol Rep 2010; 37:3561-6. [DOI: 10.1007/s11033-010-0004-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2009] [Accepted: 02/08/2010] [Indexed: 11/26/2022]
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Pérez-Sayáns M, Somoza-Martín JM, Barros-Angueira F, Rey JMG, García-García A. V-ATPase inhibitors and implication in cancer treatment. Cancer Treat Rev 2009; 35:707-13. [PMID: 19758758 DOI: 10.1016/j.ctrv.2009.08.003] [Citation(s) in RCA: 144] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2009] [Revised: 08/03/2009] [Accepted: 08/06/2009] [Indexed: 01/08/2023]
Abstract
Acidity is one of the main features of the tumors. The V-ATPase is the primary responsible for the control of tumor microenvironment by proton extrusion to the extracellular medium. The acid environment favors tissue damage, activation of destructive enzymes in the extracellular matrix, the acquisition of metastatic cell phenotypes as well as increasing the destructive capacity. The application of specific inhibitors of V-ATPases, can decrease the acidity of tumor and may allow the reduction of tumor metastasis, acting on the survival of tumor cells and prevent the phenomena of chemoresistance. Among the most important inhibitors can be distinguished benzolactone enamides (salicylihalamide), lobatamide A and B, apicularen, indolyls, oximidine, macrolactone archazolid, lobatamide C, and cruentaren. The latest generation of inhibitors includes NiK12192, FR202126, and PPI SB 242784. The purpose of this paper is to describe the latest advances in the field of V-ATPase inhibitors, describe further developments related to the classic inhibitors, and discuss new potential applications of these drugs in cancer treatment.
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86
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Zhu PJ, Hobson JP, Southall N, Qiu C, Thomas CJ, Lu J, Inglese J, Zheng W, Leppla SH, Bugge TH, Austin CP, Liu S. Quantitative high-throughput screening identifies inhibitors of anthrax-induced cell death. Bioorg Med Chem 2009; 17:5139-45. [PMID: 19540764 PMCID: PMC2795356 DOI: 10.1016/j.bmc.2009.05.054] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Revised: 05/21/2009] [Accepted: 05/22/2009] [Indexed: 11/28/2022]
Abstract
Here, we report the results of a quantitative high-throughput screen (qHTS) measuring the endocytosis and translocation of a β-lactamase-fused-lethal factor and the identification of small molecules capable of obstructing the process of anthrax toxin internalization. Several small molecules protect RAW264.7 macrophages and CHO cells from anthrax lethal toxin and protected cells from an LF-Pseudomonas exotoxin fusion protein and diphtheria toxin. Further efforts demonstrated that these compounds impaired the PA heptamer pre-pore to pore conversion in cells expressing the CMG2 receptor, but not the related TEM8 receptor, indicating that these compounds likely interfere with toxin internalization.
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Affiliation(s)
- Ping Jun Zhu
- NIH Chemical Genomics Center, National Human Genome Research Institute, National Institutes of Health, 9800 Medical Center Drive, Rockville, MD 20850, United States
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Karsdal M, Henriksen K, Leeming D, Mitchell P, Duffin K, Barascuk N, Klickstein L, Aggarwal P, Nemirovskiy O, Byrjalsen I, Qvist P, Bay-Jensen A, Dam E, Madsen S, Christiansen C. Biochemical markers and the FDA Critical Path: How biomarkers may contribute to the understanding of pathophysiology and provide unique and necessary tools for drug development. Biomarkers 2009; 14:181-202. [DOI: 10.1080/13547500902777608] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Abstract
V-ATPases constitute a ubiquitous family of heteromultimeric, proton translocating proteins. According to their localization in a multitude of eukaryotic endomembranes and plasma membranes, they energize many different transport processes. Currently, a handful of specific inhibitors of the V-ATPase are known, which represent valuable tools for the characterization of transport processes on the level of tissues, single cells or even purified proteins. The understanding of how these inhibitors function may provide a basis to develop new drugs for the benefit of patients suffering from diseases such as osteoporosis or cancer. For this purpose, it appears absolutely essential to determine the exact inhibitor binding site in a target protein on the one side and to uncover the crucial structural elements of an inhibitor on the other side. However, even for some of the most popular and long known V-ATPase inhibitors, such as bafilomycin or concanamycin, the authentic structures of their binding sites are elusive. The aim of this review is to summarize the recent advances for the old players in the inhibition game, the plecomacrolides bafilomycin and concanamycin, and to introduce some of the new players, the macrolacton archazolid, the benzolactone enamides salicylihalamide, lobatamide, apicularen, oximidine and cruentaren, and the indolyls.
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Affiliation(s)
- Markus Huss
- Department of Biology/Chemistry, University of Osnabrück, 49069 Osnabrück, Germany.
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Neutzsky-Wulff AV, Karsdal MA, Henriksen K. Characterization of the bone phenotype in ClC-7-deficient mice. Calcif Tissue Int 2008; 83:425-37. [PMID: 18958510 DOI: 10.1007/s00223-008-9185-7] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2008] [Accepted: 09/04/2008] [Indexed: 02/04/2023]
Abstract
Mice deficient in the chloride channel ClC-7, which is likely involved in acidification of the resorption lacuna, display severe osteopetrosis. To fully characterize the osteopetrotic phenotype, the phenotypes of osteoclasts and osteoblasts were evaluated. ClC-7(-/-) mice and their corresponding wild-type littermates were killed at 4-5 weeks of age. Biochemical markers of bone resorption (CTX-I), osteoclast number (TRAP5b), and osteoblast activity (ALP) were evaluated in serum. Splenocytes were differentiated into osteoclasts using M-CSF and RANKL. Mature osteoclasts were seeded on calcified or decalcified bone slices, and CTX-I, Ca(2+), and TRAP were measured. Acidification rates in membrane vesicles from bone cells were measured using acridine orange. Osteoblastogenesis and nodule formation in vitro were investigated using calvarial osteoblasts. ClC-7(-/-) osteoclasts were unable to resorb calcified bone in vitro. However, osteoclasts were able to degrade decalcified bone. Acid influx in bone membrane vesicles was reduced by 70% in ClC-7(-/-) mice. Serum ALP was increased by 30% and TRAP5b was increased by 250% in ClC-7(-/-) mice, whereas the CTX/TRAP5b ratio was reduced to 50% of the wild-type level. Finally, evaluation of calvarial ClC-7(-/-) osteoblasts showed normal osteoblastogenesis. In summary, we present evidence supporting a pivotal role for ClC-7 in acidification of the resorption lacuna and evidence indicating that bone formation and bone resorption are no longer balanced in ClC-7(-/-) mice.
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Sun S. Bone disease drug discovery: examining the interactions between osteoblast and osteoclast. Expert Opin Ther Targets 2008; 12:239-51. [DOI: 10.1517/14728222.12.2.239] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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