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McCord MC, Aizenman E. The role of intracellular zinc release in aging, oxidative stress, and Alzheimer's disease. Front Aging Neurosci 2014; 6:77. [PMID: 24860495 PMCID: PMC4028997 DOI: 10.3389/fnagi.2014.00077] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Accepted: 04/02/2014] [Indexed: 01/26/2023] Open
Abstract
Brain aging is marked by structural, chemical, and genetic changes leading to cognitive decline and impaired neural functioning. Further, aging itself is also a risk factor for a number of neurodegenerative disorders, most notably Alzheimer’s disease (AD). Many of the pathological changes associated with aging and aging-related disorders have been attributed in part to increased and unregulated production of reactive oxygen species (ROS) in the brain. ROS are produced as a physiological byproduct of various cellular processes, and are normally detoxified by enzymes and antioxidants to help maintain neuronal homeostasis. However, cellular injury can cause excessive ROS production, triggering a state of oxidative stress that can lead to neuronal cell death. ROS and intracellular zinc are intimately related, as ROS production can lead to oxidation of proteins that normally bind the metal, thereby causing the liberation of zinc in cytoplasmic compartments. Similarly, not only can zinc impair mitochondrial function, leading to excess ROS production, but it can also activate a variety of extra-mitochondrial ROS-generating signaling cascades. As such, numerous accounts of oxidative neuronal injury by ROS-producing sources appear to also require zinc. We suggest that zinc deregulation is a common, perhaps ubiquitous component of injurious oxidative processes in neurons. This review summarizes current findings on zinc dyshomeostasis-driven signaling cascades in oxidative stress and age-related neurodegeneration, with a focus on AD, in order to highlight the critical role of the intracellular liberation of the metal during oxidative neuronal injury.
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Affiliation(s)
- Meghan C McCord
- Department of Neurobiology, University of Pittsburgh School of Medicine Pittsburgh, PA, USA
| | - Elias Aizenman
- Department of Neurobiology, University of Pittsburgh School of Medicine Pittsburgh, PA, USA
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Sampson EL, Jenagaratnam L, McShane R. Metal protein attenuating compounds for the treatment of Alzheimer's dementia. Cochrane Database Syst Rev 2014; 2014:CD005380. [PMID: 24563468 PMCID: PMC10966659 DOI: 10.1002/14651858.cd005380.pub5] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Alzheimer's dementia (AD) may be caused by the formation of extracellular senile plaques comprised of beta-amyloid (Aß). In vitro and mouse model studies have demonstrated that metal protein attenuating compounds (MPACs) promote the solubilisation and clearance of Aß. OBJECTIVES To evaluate the efficacy of metal protein attenuating compounds (MPACs) for the treatment of cognitive impairment due to Alzheimer's dementia. SEARCH METHODS We searched ALOIS, the Cochrane Dementia and Cognitive Improvement Group Specialized Register, on 29 July 2010 using the terms: Clioquinol OR PBT1 OR PBT2 OR "metal protein" OR MPACS OR MPAC. SELECTION CRITERIA Randomised double-blind trials in which treatment with an MPAC was administered to participants with Alzheimer's dementia in a parallel group comparison with placebo were included. DATA COLLECTION AND ANALYSIS Three review authors (RM, LJ, ELS) independently assessed the quality of trials according to the Cochrane Handbook for Systematic Reviews of Interventions.The primary outcome measure of interest was cognitive function (as measured by psychometric tests). The secondary outcome measures of interest were in the following areas: quality of life, functional performance, effect on carer, biomarkers, safety and adverse effects, and death. MAIN RESULTS Two MPAC trials were identified. One trial compared clioquinol (PBT1) with placebo in 36 patients and 32 had sufficient data for per protocol analysis. There was no statistically significant difference in cognition (as measured on the Alzheimer's Disease Assessment Scale - Cognition (ADAS-Cog)) between the active treatment and placebo groups at 36 weeks. The difference in mean change from baseline ADAS-Cog score in the clioquinol arm compared with the placebo arm at weeks 24 and 36 was a difference of 7.37 (95% confidence interval (CI) 1.51 to 13.24) and 6.36 (95% CI -0.50 to 13.23), respectively.There was no significant impact on non-cognitive symptoms or clinical global impression. One participant in the active treatment group developed neurological symptoms (impaired visual acuity and colour vision) which resolved on cessation of treatment and were possibly attributable to the drug.In the second trial a successor compound, PBT2, was compared with placebo in 78 participants with mild Alzheimer's dementia; all were included in the intention-to-treat analysis. There was no significant difference in the Neuropsychological Test Battery (NTB) composite or memory between placebo and PBT2 in the least squares mean change from baseline at week 12. However, two executive function component tests of the NTB showed significant improvement over placebo in the PBT2 250 mg group from baseline to week 12: category fluency test (2.8 words, 95% CI 0.1 to 5.4; P = 0.041) and trail making part B (-48.0 s, 95% CI -83.0 to -13.0; P = 0.009). In the executive factor Z score, the difference in least squares mean change from baseline at week 12 for PBT2 250 mg compared with placebo was 0·27 (0·01 to 0·53; p=0·042).There was no significant effect on cognition on Mini-Mental State Examination (MMSE) or ADAS-Cog scales. PBT2 had a favourable safety profile. AUTHORS' CONCLUSIONS There is an absence of evidence as to whether clioquinol (PBT1) has any positive clinical benefit for patients with AD, or whether the drug is safe. We have some concerns about the quality of the study methodology; there was an imbalance in treatment and control groups after randomisation (participants in the active treatment group had a higher mean pre-morbid IQ) and the secondary analyses of results stratified by baseline dementia severity. The planned phase III trial of PBT1 has been abandoned and this compound has been withdrawn from development. The second trial of PBT2 was more rigorously conducted and showed that after 12 weeks this compound appeared to be safe and well tolerated in people with mild Alzheimer's dementia. Larger trials are now required to demonstrate cognitive efficacy.
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Affiliation(s)
- Elizabeth L Sampson
- University CollegeMarie Curie Palliative Care Research Unit67‐73 Riding House StreetLondonUKW1W 7EJ
| | | | - Rupert McShane
- University of OxfordRadcliffe Department of MedicineJohn Radcliffe HospitalLevel 4, Main Hospital, Room 4401COxfordOxfordshireUKOX3 9DU
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Vranec P, Potočňák I, Sabolová D, Farkasová V, Ipóthová Z, Pisarčíková J, Paulíková H. Low-dimensional compounds containing bioactive ligands. V: Synthesis and characterization of novel anticancer Pd(II) ionic compounds with quinolin-8-ol halogen derivatives. J Inorg Biochem 2014; 131:37-46. [DOI: 10.1016/j.jinorgbio.2013.10.018] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Revised: 10/21/2013] [Accepted: 10/23/2013] [Indexed: 11/27/2022]
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54
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Kharadi GJ. Effect of substituent of terpyridines on the in vitro antioxidant, antitubercular, biocidal and fluorescence studies of copper(II) complexes with clioquinol. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2014; 117:662-668. [PMID: 24128919 DOI: 10.1016/j.saa.2013.09.049] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2013] [Accepted: 09/07/2013] [Indexed: 06/02/2023]
Abstract
An octahedral complexes of copper with clioquinol(CQ) and substituted terpyridine have been synthesized. The Cu(II) complexes have been characterized by elemental analyses, thermogravimetric analyses, magnetic moment measurements, FT-IR, electronic, (1)HNMR and FAB mass spectra. Antimycobacterial screening of ligand and its copper compound against Mycobacterium tuberculosis shows clear enhancement in the antitubercular activity upon copper complexation. Ferric-reducing anti-oxidant power of all complexes were measured. The fluorescence spectra of complexes show red shift, which may be due to the chelation by the ligands to the metal ion. It enhances ligand ability to accept electrons and decreases the electron transition energy. The antimicrobial efficiency of the complexes were tested on five different microorganisms and showed good biological activity.
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Affiliation(s)
- G J Kharadi
- Department of Chemistry, Navjivan Science College, Gujarat University, Dahod 389151, Gujarat, India.
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Chen ZF, Peng Y, Gu YQ, Liu YC, Liu M, Huang KB, Hu K, Liang H. High antitumor activity of 5,7-dihalo-8-quinolinolato tin(IV) complexes. Eur J Med Chem 2013; 62:51-8. [DOI: 10.1016/j.ejmech.2012.12.030] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 12/13/2012] [Accepted: 12/15/2012] [Indexed: 11/30/2022]
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Liu YC, Chen ZF, Song XY, Peng Y, Qin QP, Liang H. Synthesis, crystal structure, cytotoxicity and DNA interaction of 5,7-dibromo-8-quinolinolato-lanthanides. Eur J Med Chem 2013; 59:168-75. [DOI: 10.1016/j.ejmech.2012.11.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2012] [Revised: 10/31/2012] [Accepted: 11/02/2012] [Indexed: 12/29/2022]
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Alfonso I, Quesada R. Biological activity of synthetic ionophores: ion transporters as prospective drugs? Chem Sci 2013. [DOI: 10.1039/c3sc50882j] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
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Chen ZF, Gu YQ, Song XY, Liu YC, Peng Y, Liang H. Synthesis, crystal structure, cytotoxicity and DNA interaction of 5,7-dichloro-8-quinolinolato-lanthanides. Eur J Med Chem 2013; 59:194-202. [DOI: 10.1016/j.ejmech.2012.10.037] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Revised: 10/19/2012] [Accepted: 10/20/2012] [Indexed: 11/26/2022]
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Patel KS, Patel JC, Dholariya HR, Patel KD. Multiple heating rate kinetic parameters, thermal, X-ray diffraction studies of newly synthesized octahedral copper complexes based on bromo-coumarins along with their antioxidant, anti-tubercular and antimicrobial activity evaluation. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2012; 96:468-479. [PMID: 22728283 DOI: 10.1016/j.saa.2012.05.057] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2012] [Revised: 05/17/2012] [Accepted: 05/26/2012] [Indexed: 06/01/2023]
Abstract
Series of new Cu(II) complexes were synthesized by classical thermal technique. The biologically potent ligands (L) were prepared by refluxing 6-brom 3-acetyl coumarin with aldehydes in the presence of piperidine in ethanol. The Cu(II) complexes have been synthesized by mixing an aqueous solution of Cu(NO(3))(2) in 1:1 molar ratios with ethanolic bidentate ligands and Clioquinol. The structures of the ligands and their copper complexes were investigated and confirmed by the elemental analysis, FT-IR, (1)H NMR, (13)C NMR, mass spectral and powder X-ray diffraction studies respectively. Thermal behaviour of newly synthesized mixed ligand Cu(II) complexes were investigated by means of thermogravimetry, differential thermogravimetry, differential scanning calorimetry, electronic spectra and magnetic measurements. Dynamic scan of DSC experiments for Cu(II) complexes were taken at different heating rates (2.5-20 °C min(-1)). Kinetic parameters for second step degradation of all complexes obtained by Kissinger's and Ozawa's methods were in good agreement. On the basis of these studies it is clear that ligands coordinated to metal atom in a monobasic bidentate mode, by OO and ON donor system. Thus, suitable octahedral geometry for hexa-coordinated state has been suggested for the metal complexes. Both the ligands as well as its complexes have been screened for their in vitro antioxidant, anti-tubercular and antimicrobial activities. All were found to be significant potent compared to parent ligands employed for complexation.
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Affiliation(s)
- Ketan S Patel
- Chemistry Department, V.P. & R.P.T.P. Science College, Sardar Patel University, Vallabh Vidhyanagar 388 120, Gujarat, India.
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60
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Scheiber IF, Dringen R. Astrocyte functions in the copper homeostasis of the brain. Neurochem Int 2012; 62:556-65. [PMID: 22982300 DOI: 10.1016/j.neuint.2012.08.017] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Revised: 08/16/2012] [Accepted: 08/30/2012] [Indexed: 12/18/2022]
Abstract
Copper is an essential element that is required for a variety of important cellular functions. Since not only copper deficiency but also excess of copper can seriously affect cellular functions, the cellular copper metabolism is tightly regulated. In brain, astrocytes appear to play a pivotal role in the copper metabolism. With their strategically important localization between capillary endothelial cells and neuronal structures they are ideally positioned to transport copper from the blood-brain barrier to parenchymal brain cells. Accordingly, astrocytes have the capacity to efficiently take up, store and to export copper. Cultured astrocytes appear to be remarkably resistant against copper-induced toxicity. However, copper exposure can lead to profound alterations in the metabolism of these cells. This article will summarize the current knowledge on the copper metabolism of astrocytes, will describe copper-induced alterations in the glucose and glutathione metabolism of astrocytes and will address the potential role of astrocytes in the copper metabolism of the brain in diseases that have been connected with disturbances in brain copper homeostasis.
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Affiliation(s)
- Ivo F Scheiber
- Center for Biomolecular Interactions Bremen, University of Bremen, P.O. Box 330440, D-28334 Bremen, Germany
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61
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Iron chelation and nanoparticle target delivery in the development of new multifunctional disease-modifying drugs for Alzheimer's disease. Ther Deliv 2012; 3:571-4. [PMID: 22834400 DOI: 10.4155/tde.12.32] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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62
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Affiliation(s)
- Kasper P Kepp
- DTU Chemistry, Technical University of Denmark, DK 2800 Kongens Lyngby, Denmark.
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63
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Tiffany-Castiglioni E, Qian Y. ER chaperone–metal interactions: Links to protein folding disorders. Neurotoxicology 2012; 33:545-57. [DOI: 10.1016/j.neuro.2012.02.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Revised: 02/07/2012] [Accepted: 02/07/2012] [Indexed: 01/09/2023]
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64
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Sampson EL, Jenagaratnam L, McShane R. Metal protein attenuating compounds for the treatment of Alzheimer's dementia. Cochrane Database Syst Rev 2012; 5:CD005380. [PMID: 22592705 PMCID: PMC4165331 DOI: 10.1002/14651858.cd005380.pub4] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND Alzheimer's dementia (AD) may be caused by the formation of extracellular senile plaques comprised of beta-amyloid (Aß). In vitro and mouse model studies have demonstrated that metal protein attenuating compounds (MPACs) promote the solubilisation and clearance of Aß. OBJECTIVES To evaluate the efficacy of metal protein attenuating compounds (MPACs) for the treatment of cognitive impairment due to Alzheimer's dementia. SEARCH METHODS We searched ALOIS, the Cochrane Dementia and Cognitive Improvement Group Specialized Register, on 29 July 2010 using the terms: Clioquinol OR PBT1 OR PBT2 OR "metal protein" OR MPACS OR MPAC. SELECTION CRITERIA Randomised double-blind trials in which treatment with an MPAC was administered to participants with Alzheimer's dementia in a parallel group comparison with placebo were included. DATA COLLECTION AND ANALYSIS Three review authors (RM, LJ, ELS) independently assessed the quality of trials according to the Cochrane Handbook for Systematic Reviews of Interventions.The primary outcome measure of interest was cognitive function (as measured by psychometric tests). The secondary outcome measures of interest were in the following areas: quality of life, functional performance, effect on carer, biomarkers, safety and adverse effects, and death. MAIN RESULTS Two MPAC trials were identified. One trial compared clioquinol (PBT1) with placebo in 36 patients and 32 had sufficient data for per protocol analysis. There was no statistically significant difference in cognition (as measured on the Alzheimer's Disease Assessment Scale - Cognition (ADAS-Cog)) between the active treatment and placebo groups at 36 weeks. The difference in mean change from baseline ADAS-Cog score in the clioquinol arm compared with the placebo arm at weeks 24 and 36 was a difference of 7.37 (95% confidence interval (CI) 1.51 to 13.24) and 6.36 (95% CI -0.50 to 13.23), respectively.There was no significant impact on non-cognitive symptoms or clinical global impression. One participant in the active treatment group developed neurological symptoms (impaired visual acuity and colour vision) which resolved on cessation of treatment and were possibly attributable to the drug.In the second trial a successor compound, PBT2, was compared with placebo in 78 participants with mild Alzheimer's dementia; all were included in the intention-to-treat analysis. There was no significant difference in the Neuropsychological Test Battery (NTB) composite, memory or executive scores between placebo and PBT2 in the least squares mean change from baseline at week 12. However, two executive function component tests of the NTB showed significant improvement over placebo in the PBT2 250 mg group from baseline to week 12: category fluency test (2.8 words, 95% CI 0.1 to 5.4; P = 0.041) and trail making part B (-48.0 s, 95% CI -83.0 to -13.0; P = 0.009). There was no significant effect on cognition on Mini-Mental State Examination (MMSE) or ADAS-Cog scales. PBT2 had a favourable safety profile. AUTHORS' CONCLUSIONS There is an absence of evidence as to whether clioquinol (PBT1) has any positive clinical benefit for patients with AD, or whether the drug is safe. We have some concerns about the quality of the study methodology; there was an imbalance in treatment and control groups after randomisation (participants in the active treatment group had a higher mean pre-morbid IQ) and the secondary analyses of results stratified by baseline dementia severity. The planned phase III trial of PBT1 has been abandoned and this compound has been withdrawn from development. The second trial of PBT2 was more rigorously conducted and showed that after 12 weeks this compound appeared to be safe and well tolerated in people with mild Alzheimer's dementia. Larger trials are now required to demonstrate cognitive efficacy.
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Affiliation(s)
- Elizabeth L Sampson
- UCL Mental Health Sciences Unit, University College Medical School, London, UK.
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65
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Low-dimensional compounds containing bioactive ligands. Part II: Palladium(II) and platinum(II) complexes with clioquinol as carboplatin analogues. Polyhedron 2012. [DOI: 10.1016/j.poly.2012.03.046] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Abstract
OBJECTIVES This paper reviews evidence of an association between zinc (Zn) nutrition and Alzheimer's disease (AD) or age-associated cognitive decline. The involvement of zinc in the pathology of AD has been reported hundreds of times. It is, however, still a matter of debate whether the disease progression can be influenced by modifying zinc in the diet. METHODS We searched Medline, Embase, Biosis, ALOIS, the Cochrane central register of controlled trials, the Cochrane database of systematic reviews, and different publisher databases, and included studies that dealt with zinc in the diet and AD or cognitive decline in elderly subjects. RESULTS Fifty-five studies met the inclusion criteria. Neither randomized-controlled trials nor observational studies provide conclusive evidence whether Zn in the diet is associated with cognitive decline or AD. Case-control and autopsy studies suggest decreased systemic and increased brain Zn levels, respectively. DISCUSSION The current state of evidence does not allow conclusions to be drawn on whether supplementation of Zn is beneficial for the prevention or treatment of AD, although a subclinical deficiency appears common in the elderly and subjects with AD. Dietary studies with animals suggest that the impact of dietary Zn on cognitive performance depend on additional nutrients. Further studies are necessary to determine whether Zn deficiency is a risk factor for AD in general terms or under certain dietary circumstances only.
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Affiliation(s)
- Martin Loef
- European University Viadrina, Institute of Transcultural Health Studies, Frankfurt (Oder), Germany/Samueli Institute, European Office, Frankfurt (Oder), Germany
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67
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Liu YC, Song XY, Chen ZF, Gu YQ, Peng Y, Liang H. Synthesis, crystal structure, DNA interaction and cytotoxicity of a dinuclear nickel(II) complex with 5,7-dichloro-8-hydroxylquinoline. Inorganica Chim Acta 2012. [DOI: 10.1016/j.ica.2011.10.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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68
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Intranasal delivery of deferoxamine reduces spatial memory loss in APP/PS1 mice. Drug Deliv Transl Res 2012; 2:160-8. [DOI: 10.1007/s13346-011-0050-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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69
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Schmitt SM, Frezza M, Dou QP. New applications of old metal-binding drugs in the treatment of human cancer. Front Biosci (Schol Ed) 2012; 4:375-91. [PMID: 22202066 DOI: 10.2741/274] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Significant advances in the use of metal complexes, precipitated by platinum, have fostered a renewed interest in harnessing their rich potential in the treatment of cancer. In addition to platinum-based complexes, the anticancer properties of other metals such as ruthenium have been realized, and ruthenium-based compounds are currently being investigated in clinical trials. Since the process of drug development can be expensive and cumbersome, finding new applications of existing drugs may provide effective means to expedite the regulatory process in bringing new drugs to the clinical setting. Encouraging findings from laboratory studies reveal significant anticancer activity from different classes of metal-chelating compounds, such as disulfiram, clioquinol, and dithiocarbamate derivatives that are currently approved for the treatment of various pathological disorders. Their use as coordination complexes with metals such as copper, zinc, and gold that target the ubiquitin-proteasome pathway have shown significant promise as potential anticancer agents. This review discusses the unique role of several selected metals in relation to their anti-cancer properties as well as the new therapeutic potential of several previously approved metal-chelating drugs. In vitro and in vivo experimental evidence along with mechanisms of action (e.g., via targeting the tumor proteasome) will also be discussed with anticipation of strengthening this exciting new concept.
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Affiliation(s)
- Sara M Schmitt
- Barbara Ann Karmanos Cancer Institute, School of Medicine, Wayne State University, Detroit, Michigan 48201, USA
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70
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Bareggi SR, Cornelli U. Clioquinol: review of its mechanisms of action and clinical uses in neurodegenerative disorders. CNS Neurosci Ther 2012; 18:41-6. [PMID: 21199452 PMCID: PMC6493473 DOI: 10.1111/j.1755-5949.2010.00231.x] [Citation(s) in RCA: 167] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Clioquinol was produced as a topical antiseptic and marketed as an oral intestinal amebicide in 1934, being used to treat a wide range of intestinal diseases. In the early 1970s, it was withdrawn from the market as an oral agent because of its association with subacute myelo-optic neuropathy (SMON), a syndrome that involves sensory and motor disturbances in the lower limbs and visual changes. The first methods for determining plasma and tissue clioquinol (5-chloro-7-iodo-8-quinolinol) levels were set up in the 1970s and involved HPLC separation with UV detection, these were followed by a more sensitive GC method with electron capture detection and a gaschromatographic-massspectrometric (GC-MS) method. Finally, an HPLC method using electrochemical detection has proved to be as highly sensitive and specific as the GC-MS. In rats, mice, rabbits, and hamsters, clioquinol is rapidily absorbed and undergoes first-pass metabolization to glucuronate and sulfate conjugates; the concentrations of the metabolites are higher than those of free clioquinol. Bioavailabilty versus intraperitoneal dosing is about 12%. Dogs and monkeys form fewer conjugates. In man, single-dose concentrations are dose related, and the drug's half-life is 11-14 h. There is no accumulation, and the drug is much less metabolized to conjugates. Clioquinol acts as a zinc and copper chelator. Metal chelation is a potential therapeutic strategy for Alzheimer's disease (AD) because zinc and copper are involved in the deposition and stabilization of amyloid plaques, and chelating agents can dissolve amyloid deposits in vitro and in vivo. In general, the ability of clioquinol to chelate and redistribute metals plays an important role in diseases characterised by Zn, Cu, Fe dyshomeostasis, such as AD and Parkinson's disease, as it reduces oxidation and the amyloid burden. Zinc chelators may also act as anticancer agents. Animal toxicity studies have revealed species-specific differences in neurotoxic responses that are related to the serum levels of clioquinol and metabolites. This is also true in humans, who form fewer conjugates. The results of studies of Alzheimer patients are conflicting and need further confirmation. The potential therapeutic role of the two main effects of MPACs (the regulation of the distribution of metals and antioxidants) has not yet been fully explored.
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Affiliation(s)
- Silvio R Bareggi
- Department of Pharmacology, Chemotherapy and Medical Toxicology, School of Medicine, University of Milan, Italy.
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71
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Zhou T, Ma Y, Kong X, Hider RC. Design of iron chelators with therapeutic application. Dalton Trans 2012; 41:6371-89. [DOI: 10.1039/c2dt12159j] [Citation(s) in RCA: 116] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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72
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de la Monte SM. Therapeutic targets of brain insulin resistance in sporadic Alzheimer's disease. Front Biosci (Elite Ed) 2012. [PMID: 22201977 DOI: 10.2741/482] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Growing evidence supports roles for brain insulin and insulin-like growth factor (IGF) resistance and metabolic dysfunction in the pathogenesis of Alzheimer's disease (AD). Whether the underlying problem stems from a primary disorder of central nervous system (CNS) neurons and glia, or secondary effects of systemic diseases such as obesity, Type 2 diabetes, or metabolic syndrome, the end-results include impaired glucose utilization, mitochondrial dysfunction, increased oxidative stress, neuroinflammation, and the propagation of cascades that result in the accumulation of neurotoxic misfolded, aggregated, and ubiquitinated fibrillar proteins. This article reviews the roles of impaired insulin and IGF signaling to AD-associated neuronal loss, synaptic disconnection, tau hyperphosphorylation, amyloid-beta accumulation, and impaired energy metabolism, and discusses therapeutic strategies and lifestyle approaches that could be used to prevent, delay the onset, or reduce the severity of AD. Finally, it is critical to recognize that AD is heterogeneous and has a clinical course that fully develops over a period of several decades. Therefore, early and multi-modal preventive and treatment approaches should be regarded as essential.
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Affiliation(s)
- Suzanne M de la Monte
- Department of Neurology, Rhode Island Hospital and Alpert Medical School of Brown University, Providence, RI, USA.
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Stone JG, Casadesus G, Gustaw-Rothenberg K, Siedlak SL, Wang X, Zhu X, Perry G, Castellani RJ, Smith MA. Frontiers in Alzheimer's disease therapeutics. Ther Adv Chronic Dis 2011; 2:9-23. [PMID: 21743833 DOI: 10.1177/2040622310382817] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Alzheimer disease (AD) is a progressive neurodegenerative disease which begins with insidious deterioration of higher cognition and progresses to severe dementia. Clinical symptoms typically involve impairment of memory and at least one other cognitive domain. Because of the exponential increase in the incidence of AD with age, the aging population across the world has seen a congruous increase AD, emphasizing the importance of disease altering therapy. Current therapeutics on the market, including cholinesterase inhibitors and N-methyl-D-aspartate receptor antagonists, provide symptomatic relief but do not alter progression of the disease. Therefore, progress in the areas of prevention and disease modification may be of critical interest. In this review, we summarize novel AD therapeutics that are currently being explored, and also mechanisms of action of specific drugs within the context of current knowledge of AD pathologic pathways.
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Affiliation(s)
- Jeremy G Stone
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio, USA
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Fazil M, Shadab, Baboota S, Sahni JK, Ali J. Nanotherapeutics for Alzheimer’s disease (AD): Past, present and future. J Drug Target 2011; 20:97-113. [DOI: 10.3109/1061186x.2011.607499] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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75
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Grabrucker AM, Rowan M, Garner CC. Brain-Delivery of Zinc-Ions as Potential Treatment for Neurological Diseases: Mini Review. DRUG DELIVERY LETTERS 2011; 1:13-23. [PMID: 22102982 PMCID: PMC3220161 DOI: 10.2174/2210303111101010013] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Homeostasis of metal ions such as Zn(2+) is essential for proper brain function. Moreover, the list of psychiatric and neurodegenerative disorders involving a dysregulation of brain Zn(2+)-levels is long and steadily growing, including Parkinson's and Alzheimer's disease as well as schizophrenia, attention deficit and hyperactivity disorder, depression, amyotrophic lateral sclerosis, Down's syndrome, multiple sclerosis, Wilson's disease and Pick's disease. Furthermore, alterations in Zn(2+)-levels are seen in transient forebrain ischemia, seizures, traumatic brain injury and alcoholism. Thus, the possibility of altering Zn(2+)-levels within the brain is emerging as a new target for the prevention and treatment of psychiatric and neurological diseases. Although the role of Zn(2+) in the brain has been extensively studied over the past decades, methods for controlled regulation and manipulation of Zn(2+) concentrations within the brain are still in their infancy. Since the use of dietary Zn(2+) supplementation and restriction has major limitations, new methods and alternative approaches are currently under investigation, such as the use of intracranial infusion of Zn(2+) chelators or nanoparticle technologies to elevate or decrease intracellular Zn(2+) levels. Therefore, this review briefly summarizes the role of Zn(2+) in psychiatric and neurodegenerative diseases and highlights key findings and impediments of brain Zn(2+)-level manipulation. Furthermore, some methods and compounds, such as metal ion chelation, redistribution and supplementation that are used to control brain Zn(2+)-levels in order to treat brain disorders are evaluated.
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Affiliation(s)
- Andreas M. Grabrucker
- Department of Psychiatry and Behavioral Sciences, Stanford School of Medicine, Stanford University, Stanford, CA, USA
| | - Magali Rowan
- Department of Psychiatry and Behavioral Sciences, Stanford School of Medicine, Stanford University, Stanford, CA, USA
| | - Craig C. Garner
- Department of Psychiatry and Behavioral Sciences, Stanford School of Medicine, Stanford University, Stanford, CA, USA
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76
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Abstract
Fe and Cu could represent dietary risk factors for Alzheimer's disease (AD), which has become a global health concern. To establish the relationship between diets high in Cu and Fe and cognitive decline or AD, we have conducted a systematic review of the literature (up to January 2011). We identified two meta-analyses, two systematic reviews, eleven placebo-controlled trials, five observational studies, forty-five case-control studies, thirty autopsy and five uncontrolled studies, and one case report. There were eleven interventional trials that tried to either supplement or deplete Fe and Cu, but none of them provided clear evidence of a beneficial effect on cognitive performance in patients with AD. The prospective studies revealed an association between a diet simultaneously high in SFA and Cu and cognitive decline. Case-control and autopsy studies showed elevated Fe levels in the brains of AD patients, whereas the evidence was less consistent for Cu. In most of the studies, Cu concentrations were unchanged in the cerebrospinal fluid and the brain but increased in the serum. In conclusion, the existing data suggest that diets excessive in Fe or Cu, together with a high intake of SFA, should be avoided in the elderly who are not at risk of anaemia. Basic studies and, building on this, clinical investigations are needed to further elucidate in which dietary patterns and in which patient groups an Fe- and Cu-rich diet might foster the risk of developing AD.
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Jiang H, Taggart JE, Zhang X, Benbrook DM, Lind SE, Ding WQ. Nitroxoline (8-hydroxy-5-nitroquinoline) is more a potent anti-cancer agent than clioquinol (5-chloro-7-iodo-8-quinoline). Cancer Lett 2011; 312:11-7. [PMID: 21899946 DOI: 10.1016/j.canlet.2011.06.032] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Revised: 05/06/2011] [Accepted: 06/24/2011] [Indexed: 11/26/2022]
Abstract
Clioquinol has been shown to have anticancer activity both in vitro and in vivo. The present study compared the cytotoxicity of clioquinol with six analogues using human cancer cell lines. Of the analogues tested, 8-hydroxy-5-nitroquinoline (NQ) was the most toxic, with an IC(50) that was five to ten fold lower than that of other congeners. Its activity was enhanced by copper, but not zinc, and the use of a zinc-sensitive fluorophore showed that unlike clioquinol, NQ is not a zinc ionophore. NQ increased intracellular reactive oxygen species generation, an effect that was significantly enhanced by the addition of copper at levels approximately the same as those found in human plasma. NQ has been used in humans for the treatment of urinary infections. NQ is an 8-hydroxyquinoline derivative that is more potent than the halogenated 8-hydroxyquinolines, and it may be less neurotoxic because it lacks zinc ionophore activity. NQ is another clinically used anti-microbial agent whose properties suggest that it may be useful in treating cancer.
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Affiliation(s)
- Hongchao Jiang
- Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
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78
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Gaeta A, Molina-Holgado F, Kong XL, Salvage S, Fakih S, Francis PT, Williams RJ, Hider RC. Synthesis, physical–chemical characterisation and biological evaluation of novel 2-amido-3-hydroxypyridin-4(1H)-ones: Iron chelators with the potential for treating Alzheimer’s disease. Bioorg Med Chem 2011; 19:1285-97. [DOI: 10.1016/j.bmc.2010.12.007] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2010] [Revised: 11/26/2010] [Accepted: 12/03/2010] [Indexed: 12/22/2022]
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79
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Ghalkhani M, Fernandes IP, Oliveira SCB, Shahrokhian S, Oliveira–Brett AM. Anodic behavior of clioquinol at a glassy carbon electrode. Bioelectrochemistry 2011; 80:175-81. [DOI: 10.1016/j.bioelechem.2010.10.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Revised: 10/08/2010] [Accepted: 10/10/2010] [Indexed: 11/25/2022]
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80
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Chen ZF, Song XY, Peng Y, Hong X, Liu YC, Liang H. High cytotoxicity of dihalo-substituted 8-quinolinolato-lanthanides. Dalton Trans 2011; 40:1684-92. [PMID: 21258737 DOI: 10.1039/c0dt01310b] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Zhen-Feng Chen
- Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources, Ministry of Education China, School of Chemistry & Chemical Engineering of Guangxi Normal University, Guilin 541004, PR China.
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81
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Hider RC, Roy S, Ma YM, Le Kong X, Preston J. The potential application of iron chelators for the treatment of neurodegenerative diseases. Metallomics 2011; 3:239-49. [DOI: 10.1039/c0mt00087f] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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82
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Salvador GA, Uranga RM, Giusto NM. Iron and mechanisms of neurotoxicity. Int J Alzheimers Dis 2010; 2011:720658. [PMID: 21234369 PMCID: PMC3014724 DOI: 10.4061/2011/720658] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Accepted: 11/10/2010] [Indexed: 01/21/2023] Open
Abstract
The accumulation of transition metals (e.g., copper, zinc, and iron) and the dysregulation of their metabolism are a hallmark in the pathogenesis of several neurodegenerative diseases. This paper will be focused on the mechanism of neurotoxicity mediated by iron. This metal progressively accumulates in the brain both during normal aging and neurodegenerative processes. High iron concentrations in the brain have been consistently observed in Alzheimer's (AD) and Parkinson's (PD) diseases. In this connection, metalloneurobiology has become extremely important in establishing the role of iron in the onset and progression of neurodegenerative diseases. Neurons have developed several protective mechanisms against oxidative stress, among them, the activation of cellular signaling pathways. The final response will depend on the identity, intensity, and persistence of the oxidative insult. The characterization of the mechanisms mediating the effects of iron-induced increase in neuronal dysfunction and death is central to understanding the pathology of a number of neurodegenerative disorders.
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Affiliation(s)
- Gabriela A Salvador
- Instituto de Investigaciones Bioquímicas Bahía Blanca, Universidad Nacional del Sur y Consejo Nacional de Investigaciones Científicas y Técnicas, 8000 Bahía Blanca, Argentina
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83
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Observations on screening-based research and some concerning trends in the literature. Future Med Chem 2010; 2:1529-46. [DOI: 10.4155/fmc.10.237] [Citation(s) in RCA: 143] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Academic drug discovery is being accompanied by a plethora of publications that report screening hits as good starting points for drug discovery or as useful tool compounds, whereas in many cases this is not so. These compounds may be protein-reactive but can also interfere in bioassays via a number of other means, and it can be very hard to prove early on that they represent false starts. This, for instance, makes it difficult for journals in their assessment of manuscripts submitted for publication. Wider awareness and recognition of these problematic compounds will help the academic drug-discovery community focus on and publish genuinely optimizable screening hits. This will be of general benefit.
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84
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Zheng Z, White C, Lee J, Peterson TS, Bush AI, Sun GY, Weisman GA, Petris MJ. Altered microglial copper homeostasis in a mouse model of Alzheimer's disease. J Neurochem 2010; 114:1630-8. [PMID: 20626553 DOI: 10.1111/j.1471-4159.2010.06888.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Alzheimer's disease (AD) is characterized by progressive neurodegeneration associated with the aggregation and deposition of β-amyloid (Aβ(40) and Aβ(42) ) peptide in senile plaques. Recent studies suggest that copper may play an important role in AD pathology. Copper concentrations are elevated in amyloid plaques and copper binds with high affinity to the Aβ peptide and promotes Aβ oligomerization and neurotoxicity. Despite this connection between copper and AD, it is unknown whether the expression of proteins involved in regulating copper homeostasis is altered in this disorder. In this study, we demonstrate that the copper transporting P-type ATPase, ATP7A, is highly expressed in activated microglial cells that are specifically clustered around amyloid plaques in the TgCRND8 mouse model of AD. Using a cultured microglial cell line, ATP7A expression was found to be increased by the pro-inflammatory cytokine interferon-gamma, but not by TNF-α or IL-1β. Interferon-gamma also elicited marked changes in copper homeostasis, including copper-dependent trafficking of ATP7A from the Golgi to cytoplasmic vesicles, increased copper uptake and elevated expression of the CTR1 copper importer. These findings suggest that pro-inflammatory conditions associated with AD cause marked changes in microglial copper trafficking, which may underlie the changes in copper homeostasis in AD. It is concluded that copper sequestration by microglia may provide a neuroprotective mechanism in AD.
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Affiliation(s)
- Zhiqiang Zheng
- Department of Nutritional Sciences and Exercise Physiology, University of Missouri, Columbia, Missouri 65211-7310, USA
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85
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Clioquinol inhibits zinc-triggered caspase activation in the hippocampal CA1 region of a global ischemic gerbil model. PLoS One 2010; 5:e11888. [PMID: 20686690 PMCID: PMC2912365 DOI: 10.1371/journal.pone.0011888] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Accepted: 07/09/2010] [Indexed: 11/29/2022] Open
Abstract
Background Excessive release of chelatable zinc from excitatory synaptic vesicles is involved in the pathogenesis of selective neuronal cell death following transient forebrain ischemia. The present study was designed to examine the neuroprotective effect of a membrane-permeable zinc chelator, clioquinol (CQ), in the CA1 region of the gerbil hippocampus after transient global ischemia. Methodology/Principal Findings The common carotid arteries were occluded bilaterally, and CQ (10 mg/kg, i.p.) was injected into gerbils once a day. The zinc chelating effect of CQ was examined with TSQ fluorescence and autometallography. Neuronal death, the expression levels of caspases and apoptosis inducing factor (AIF) were evaluated using TUNEL, in situ hybridization and Western blotting, respectively. We were able to show for the first time that CQ treatment attenuates the ischemia-induced zinc accumulation in the CA1 pyramidal neurons, accompanied by less neuronal loss in the CA1 field of the hippocampus after ischemia. Furthermore, the expression levels of caspase-3, -9, and AIF were significantly decreased in the hippocampus of CQ-treated gerbils. Conclusions/Significance The present study indicates that the neuroprotective effect of CQ is related to downregulation of zinc-triggered caspase activation in the hippocampal CA1 region of gerbils with global ischemia.
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86
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Abstract
Compounds that bind metals such as copper and zinc have many biological activities, including the ability to induce apoptosis in cancer cells. Although some of these compounds have been considered to act as chelators of metals, decreasing their bioavailability, others increase intracellular metal concentrations. We review recent work regarding the recognition of the biological effects of metal ionophores with different structures, particularly with regard to their actions upon cancer cells focusing on dithiocarbamates, pyrithione, and the 8-hydroxyquinoline derivative, clioquinol. We provide a biologically based classification of metal-binding compounds that allows an experimental distinction between chelators and ionophores that can be readily used by biologists, which may lead to further study and classification of metal-binding drugs. Metal ionophores may kill cancer cells by a number of mechanisms, including lysosomal disruption and proteasome inhibition, and likely others. Because some of these compounds have been safely administered to animals and humans, they have the potential to become clinically useful anticancer agents.
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Affiliation(s)
- Wei-Qun Ding
- Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
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87
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Green DE, Bowen ML, Scott LE, Storr T, Merkel M, Böhmerle K, Thompson KH, Patrick BO, Schugar HJ, Orvig C. In vitro studies of 3-hydroxy-4-pyridinones and their glycosylated derivatives as potential agents for Alzheimer's disease. Dalton Trans 2010; 39:1604-15. [DOI: 10.1039/b918439b] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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88
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Beyer N, Coulson DT, Heggarty S, Ravid R, Irvine GB, Hellemans J, Johnston JA. ZnT3 mRNA levels are reduced in Alzheimer's disease post-mortem brain. Mol Neurodegener 2009; 4:53. [PMID: 20030848 PMCID: PMC2806356 DOI: 10.1186/1750-1326-4-53] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2009] [Accepted: 12/23/2009] [Indexed: 12/28/2022] Open
Abstract
Background ZnT3 is a membrane Zn2+ transporter that is responsible for concentrating Zn2+ into neuronal presynaptic vesicles. Zn2+ homeostasis in the brain is relevant to Alzheimer's disease (AD) because Zn2+ released during neurotransmission may bind to Aβ peptides, accelerating the assembly of Aβ into oligomers which have been shown to impair synaptic function. Results We quantified ZnT3 mRNA levels in Braak-staged human post mortem (pm) brain tissue from medial temporal gyrus, superior occipital gyrus, superior parietal gyrus, superior frontal gyrus and cerebellum from individuals with AD (n = 28), and matched controls (n = 5) using quantitative real-time PCR. ZnT3 mRNA levels were significantly decreased in all four cortical regions examined in the AD patients, to 45-60% of control levels. This reduction was already apparent at Braak stage 4 in most cortical regions examined. Quantification of neuronal and glial-specific markers in the same samples (neuron-specific enolase, NSE; and glial fibrillary acidic protein, GFAP) indicated that loss of cortical ZnT3 expression was more pronounced, and occurred prior to, significant loss of NSE expression in the tissue. Significant increases in cortical GFAP expression were apparent as the disease progressed. No gene expression changes were observed in the cerebellum, which is relatively spared of AD neuropathology. Conclusions This first study to quantify ZnT3 mRNA levels in human pm brain tissue from individuals with AD and controls has revealed a significant loss of ZnT3 expression in cortical regions, suggesting that neuronal cells in particular show reduced expression of ZnT3 mRNA in the disease. This suggests that altered neuronal Zn2+ handling may be an early event in AD pathogenesis.
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Affiliation(s)
- Nancy Beyer
- Centre for Public Health, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Northern Ireland
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89
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Hegde ML, Bharathi P, Suram A, Venugopal C, Jagannathan R, Poddar P, Srinivas P, Sambamurti K, Rao KJ, Scancar J, Messori L, Zecca L, Zatta P. Challenges associated with metal chelation therapy in Alzheimer's disease. J Alzheimers Dis 2009; 17:457-68. [PMID: 19363258 DOI: 10.3233/jad-2009-1068] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A close association between brain metal dishomeostasis and the onset and/or progression of Alzheimer's disease (AD) has been clearly established in a number of studies, although the underlying biochemical mechanisms remain obscure. This observation renders chelation therapy an attractive pharmacological option for the treatment of this disease. However, a number of requirements must be fulfilled in order to adapt chelation therapy to AD so that the term "metal targeted strategies" seems now more appropriate. Indeed, brain metal redistribution rather than brain metal scavenging and removal is the major goal of this type of intervention. The most recent developments in metal targeted strategies for AD will be discussed using, as useful examples, clioquinol, curcumin, and epigallocatechin, and the future perspectives will also be outlined.
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Affiliation(s)
- Muralidhar L Hegde
- Department of Biochemistry and Nutrition, Central Food Technological Research Institute, Mysore, India
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Chapter 5 - Development of iron chelator-nanoparticle conjugates as potential therapeutic agents for Alzheimer disease. PROGRESS IN BRAIN RESEARCH 2009; 180:97-108. [PMID: 20302830 DOI: 10.1016/s0079-6123(08)80005-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Oxidative stress is known to play a key role in the initiation and promotion of the neurodegeneration that characterizes the pathogenesis of Alzheimer disease (AD). An accumulation of redox active transition metals, including iron and copper, is likely a major generator of reactive oxidative species and other free radicals and is thought to induce a detrimental cycle of oxidative stress, amyloid-beta aggregation, and neurodegeneration. As such, metal chelators may provide an alternative therapeutic approach to sequester redox active metals and prevent the onslaught of oxidative damage. Unfortunately, however, metal chelation approaches are currently limited in their potential, since many cannot readily pass the blood-brain barrier (BBB), due to their hydrophilicity, and many are neurotoxic at high concentrations. To circumvent such issues, here we describe the development of iron chelator-nanoparticle conjugation that allows delivery of target chelator to the brain in the absence of neurotoxicity. Such nanoparticle delivery of iron chelators will likely provide a highly advantageous mode of attack on the oxidative stress that plagues AD as well as other conditions characterized by excess metal accumulation.
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91
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Copper in the brain and Alzheimer’s disease. J Biol Inorg Chem 2009; 15:61-76. [DOI: 10.1007/s00775-009-0600-y] [Citation(s) in RCA: 313] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2009] [Accepted: 10/13/2009] [Indexed: 12/13/2022]
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92
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Liu G, Men P, Perry G, Smith MA. Metal chelators coupled with nanoparticles as potential therapeutic agents for Alzheimer's disease. ACTA ACUST UNITED AC 2009; 1:42-55. [PMID: 19936278 DOI: 10.1166/jns.2009.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Alzheimer's disease (AD) is a devastating neuro-degenerative disorder characterized by the progressive and irreversible loss of memory followed by complete dementia. Despite the disease's high prevalence and great economic and social burden, an explicative etiology or viable cure is not available. Great effort has been made to better understand the disease's pathogenesis, and to develop more effective therapeutic agents. However, success is greatly hampered by the presence of the blood-brain barrier that limits a large number of potential therapeutics from entering the brain. Nanoparticle-mediated drug delivery is one of the few valuable tools for overcoming this impediment and its application as a potential AD treatment shows promise. In this review, the current studies on nanoparticle delivery of chelation agents as possible therapeutics for AD are discussed because several metals are found excessive in the AD brain and may play a role in the disease development. Specifically, a novel approach involving transport of iron chelation agents into and out of the brain by nanoparticles is highlighted. This approach may provide a safer and more effective means of simultaneously reducing several toxic metals in the AD brain. It may also provide insights into the mechanisms of AD pathophysiology, and prove useful in treating other iron-associated neurodegenerative diseases such as Friedreich's ataxia, Parkinson's disease, Huntington's disease and Hallervorden-Spatz Syndrome. It is important to note that the use of nanoparticle-mediated transport to facilitate toxicant excretion from diseased sites in the body may advance nanoparticle technology, which is currently focused on targeted drug delivery for disease prevention and treatment. The application of nanoparticle-mediated drug transport in the treatment of AD is at its very early stages of development and, therefore, more studies are warranted.
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Affiliation(s)
- Gang Liu
- Department of Radiology, University of Utah, Salt Lake City, UT 84108, USA
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93
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Tuller ER, Brock AL, Yu H, Lou JR, Benbrook DM, Ding WQ. PPARα signaling mediates the synergistic cytotoxicity of clioquinol and docosahexaenoic acid in human cancer cells. Biochem Pharmacol 2009; 77:1480-6. [DOI: 10.1016/j.bcp.2009.02.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2008] [Revised: 01/29/2009] [Accepted: 02/05/2009] [Indexed: 11/29/2022]
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94
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Liu G, Men P, Kudo W, Perry G, Smith MA. Nanoparticle-chelator conjugates as inhibitors of amyloid-beta aggregation and neurotoxicity: a novel therapeutic approach for Alzheimer disease. Neurosci Lett 2009; 455:187-90. [PMID: 19429118 DOI: 10.1016/j.neulet.2009.03.064] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2009] [Revised: 03/18/2009] [Accepted: 03/19/2009] [Indexed: 01/06/2023]
Abstract
Oxidative stress and amyloid-beta are considered major etiological and pathological factors in the initiation and promotion of neurodegeneration in Alzheimer disease (AD). Insomuch as causes of such oxidative stress, transition metals, such as iron and copper, which are found in high concentrations in the brains of AD patients and accumulate specifically in the pathological lesions, are viewed as key contributors to the altered redox state. Likewise, the aggregation and toxicity of amyloid-beta is dependent upon transition metals. As such, chelating agents that selectively bind to and remove and/or "redox silence" transition metals have long been considered as attractive therapies for AD. However, the blood-brain barrier and neurotoxicity of many traditional metal chelators has limited their utility in AD or other neurodegenerative disorders. To circumvent this, we previously suggested that nanoparticles conjugated to iron chelators may have the potential to deliver chelators into the brain and overcome such issues as chelator bioavailability and toxic side-effects. In this study, we synthesized a prototype nanoparticle-chelator conjugate (Nano-N2PY) and demonstrated its ability to protect human cortical neurons from amyloid-beta-associated oxidative toxicity. Furthermore, Nano-N2PY nanoparticle-chelator conjugates effectively inhibited amyloid-beta aggregate formation. Overall, this study indicates that Nano-N2PY, or other nanoparticles conjugated to metal chelators, may provide a novel therapeutic strategy for AD and other neurodegenerative diseases associated with excess transition metals.
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Affiliation(s)
- Gang Liu
- Department of Radiology, University of Utah, Salt Lake City, UT 84108, USA.
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95
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Behbehani RG. A novel method for thermodynamic study on binding of copper ion with Alzheimer’s amyliod β peptide. Sci Bull (Beijing) 2009. [DOI: 10.1007/s11434-009-0065-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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96
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Kell DB. Iron behaving badly: inappropriate iron chelation as a major contributor to the aetiology of vascular and other progressive inflammatory and degenerative diseases. BMC Med Genomics 2009; 2:2. [PMID: 19133145 PMCID: PMC2672098 DOI: 10.1186/1755-8794-2-2] [Citation(s) in RCA: 364] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2008] [Accepted: 01/08/2009] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular 'reactive oxygen species' (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. REVIEW We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation).The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible.This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, since in some circumstances (especially the presence of poorly liganded iron) molecules that are nominally antioxidants can actually act as pro-oxidants. The reduction of redox stress thus requires suitable levels of both antioxidants and effective iron chelators. Some polyphenolic antioxidants may serve both roles.Understanding the exact speciation and liganding of iron in all its states is thus crucial to separating its various pro- and anti-inflammatory activities. Redox stress, innate immunity and pro- (and some anti-)inflammatory cytokines are linked in particular via signalling pathways involving NF-kappaB and p38, with the oxidative roles of iron here seemingly involved upstream of the IkappaB kinase (IKK) reaction. In a number of cases it is possible to identify mechanisms by which ROSs and poorly liganded iron act synergistically and autocatalytically, leading to 'runaway' reactions that are hard to control unless one tackles multiple sites of action simultaneously. Some molecules such as statins and erythropoietin, not traditionally associated with anti-inflammatory activity, do indeed have 'pleiotropic' anti-inflammatory effects that may be of benefit here. CONCLUSION Overall we argue, by synthesising a widely dispersed literature, that the role of poorly liganded iron has been rather underappreciated in the past, and that in combination with peroxide and superoxide its activity underpins the behaviour of a great many physiological processes that degrade over time. Understanding these requires an integrative, systems-level approach that may lead to novel therapeutic targets.
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Affiliation(s)
- Douglas B Kell
- School of Chemistry and Manchester Interdisciplinary Biocentre, The University of Manchester, 131 Princess St, Manchester, M1 7DN, UK.
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Storr T, Scott LE, Bowen ML, Green DE, Thompson KH, Schugar HJ, Orvig C. Glycosylated tetrahydrosalens as multifunctional molecules for Alzheimer's therapy. Dalton Trans 2009:3034-43. [DOI: 10.1039/b902545f] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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98
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Abstract
We have previously demonstrated that clioquinol (5-chloro-7-iodo-8-hydroxyquinoline) acts as a zinc ionophore and induces apoptosis of human cancer cells; however, the mechanisms of clioquinol/zinc-induced apoptotic cell death remain to be elucidated further. Using fluorescence-labelled probes, the present study has examined intracellular zinc distribution after clioquinol treatment in human cancer cells in order to identify cellular targets for zinc ionophores. DU 145, a human prostate cancer line, was chosen as a model system for the present study, and results were confirmed in other human cancer cell lines. Although treatment of cancer cells with 50 μM ZnCl2 for 3 days had no effect on cell viability, addition of clioquinol dramatically enhanced the cytotoxicity, confirming our previous observations. The ionophore activity of clioquinol was confirmed using fluorescence microscopy. Intracellular free zinc was found to be concentrated in lysosomes, indicating that lysosomes are the primary target of zinc ionophores. Furthermore, lysosomal integrity was disrupted after addition of clioquinol and zinc to the cells, as shown by redistribution of both Acridine Orange and cathepsin D. Clioquinol plus zinc resulted in a cleavage of Bid (BH3-interacting domain death agonist), a hallmark of lysosome-mediated apoptotic cell death. Thus the present study demonstrates for the first time that clioquinol generates free zinc in lysosomes, leading to their disruption and apoptotic cell death.
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Ismail T, Mauerhofer E, Slomianka L. The hippocampal region of rats and mice after a single i.p. dose of clioquinol: Loss of synaptic zinc, cell death and c-Fos induction. Neuroscience 2008; 157:697-707. [DOI: 10.1016/j.neuroscience.2008.09.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2008] [Revised: 09/05/2008] [Accepted: 09/05/2008] [Indexed: 01/28/2023]
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100
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Biran Y, Masters CL, Barnham KJ, Bush AI, Adlard PA. Pharmacotherapeutic targets in Alzheimer's disease. J Cell Mol Med 2008; 13:61-86. [PMID: 19040415 PMCID: PMC3823037 DOI: 10.1111/j.1582-4934.2008.00595.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder which is characterized by an increasing impairment in normal memory and cognitive processes that significantly diminishes a person's daily functioning. Despite decades of research and advances in our understanding of disease aetiology and pathogenesis, there are still no effective disease-modifying drugs available for the treatment of AD. However, numerous compounds are currently undergoing pre-clinical and clinical evaluations. These candidate pharma-cotherapeutics are aimed at various aspects of the disease, such as the microtubule-associated τ-protein, the amyloid-β (Aβ) peptide and metal ion dyshomeostasis – all of which are involved in the development and progression of AD. We will review the way these pharmacological strategies target the biochemical and clinical features of the disease and the investigational drugs for each category.
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Affiliation(s)
- Yif'at Biran
- The Oxidation Biology Laboratory, The Mental Health Research Institute, Parkville, Victoria, Australia
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