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Boada M, Ramos-Fernández E, Guivernau B, Muñoz FJ, Costa M, Ortiz AM, Jorquera JI, Núñez L, Torres M, Páez A. Treatment of Alzheimer disease using combination therapy with plasma exchange and haemapheresis with albumin and intravenous immunoglobulin: Rationale and treatment approach of the AMBAR (Alzheimer Management By Albumin Replacement) study. Neurologia 2014; 31:473-81. [PMID: 25023458 DOI: 10.1016/j.nrl.2014.02.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 02/02/2014] [Indexed: 10/25/2022] Open
Abstract
INTRODUCTION There is a growing interest in new therapeutic strategies for the treatment of Alzheimer disease (AD) which focus on reducing the beta-amyloid peptide (Aβ) burden in the brain by sequestering plasma Aβ, a large proportion of which is bound to albumin and other proteins. This review discusses the concepts of interaction between Aβ and albumin that have given rise to AMBAR (Alzheimer's Disease Management by Albumin Replacement) project, a new multicentre, randomised, controlled clinical trial for the treatment of AD. DEVELOPMENT Results from preliminary research suggest that Albutein(®) (therapeutic albumin, Grifols) contains no quantifiable levels of Aβ. Studies also show that Albutein(®) has Aβ binding capacity. On the other hand, AD entails a high level of nitro-oxidative stress associated with fibrillar aggregates of Aβ that can induce albumin modification, thus affecting its biological functions. Results from the phase ii study confirm that using therapeutic apheresis to replace endogenous albumin with Albutein(®) 5% is feasible and safe in patients with AD. This process resulted in mobilisation of Aβ and cognitive improvement in treated patients. The AMBAR study will test combination therapy with therapeutic apheresis and haemopheresis with the possible leverage effect of Albutein(®) with intravenous immunoglobulin replacement (Flebogamma(®) DIF). Cognitive, functional, and behavioural changes in patients with mild to moderate AD will be assessed. CONCLUSIONS the AMBAR study represents a new therapeutic perspective for AD.
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Affiliation(s)
- M Boada
- Fundació ACE, Institut Català de Neurociències Aplicades, Barcelona, España; Hospital Universitari Vall d'Hebron-Institut de Recerca, Universitat Autònoma de Barcelona (VHIR-UAB), Barcelona, España.
| | - E Ramos-Fernández
- Laboratorio de Fisiología Molecular y Canalopatías, Departamento de Ciencias Experimentales y de la Salud, Universitat Pompeu Fabra, Barcelona, España
| | - B Guivernau
- Laboratorio de Fisiología Molecular y Canalopatías, Departamento de Ciencias Experimentales y de la Salud, Universitat Pompeu Fabra, Barcelona, España
| | - F J Muñoz
- Laboratorio de Fisiología Molecular y Canalopatías, Departamento de Ciencias Experimentales y de la Salud, Universitat Pompeu Fabra, Barcelona, España
| | - M Costa
- Área de Investigación y Desarrollo, Grifols, Barcelona, España
| | - A M Ortiz
- Área de Investigación y Desarrollo, Grifols, Barcelona, España
| | - J I Jorquera
- Área de Investigación y Desarrollo, Grifols, Barcelona, España
| | - L Núñez
- Departamento de Ensayos Clínicos y Farmacovigilancia, Grifols, Barcelona, España
| | - M Torres
- Departamento de Ensayos Clínicos y Farmacovigilancia, Grifols, Barcelona, España
| | - A Páez
- Departamento de Ensayos Clínicos y Farmacovigilancia, Grifols, Barcelona, España
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102
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Genetic markers for diagnosis and pathogenesis of Alzheimer's disease. Gene 2014; 545:185-93. [DOI: 10.1016/j.gene.2014.05.031] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 04/07/2014] [Accepted: 05/13/2014] [Indexed: 02/06/2023]
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103
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Detection and quantification of plasma amyloid-β by selected reaction monitoring mass spectrometry. Anal Chim Acta 2014; 840:1-9. [PMID: 25086887 DOI: 10.1016/j.aca.2014.06.024] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 05/29/2014] [Accepted: 06/16/2014] [Indexed: 01/25/2023]
Abstract
Amyloid-β (Aβ) in human plasma was detected and quantified by an antibody-free method, selected reaction monitoring mass spectrometry (SRM-MS) in the current study. Due to its low abundance, SRM-based quantification in 10 μL plasma was a challenge. Prior to SRM analysis, human plasma proteins as a whole were digested by trypsin and high pH reversed-phase liquid chromatography (RPLC) was used to fractionate the tryptic digests and to collect peptides, Aβ(1-5), Aβ(6-16), Aβ(17-28) and Aβ(29-40(42)) of either Aβ(1-40) or Aβ(1-42). Among those peptides, Aβ(17-28) was selected as a surrogate to measure the total Aβ level. Human plasma samples obtained from triplicate sample preparations were analyzed, obtaining 4.20 ng mL(-1) with a CV of 25.3%. Triplicate measurements for each sample preparation showed CV of <5%. Limit of quantification was obtained as 132 pM, which corresponded to 570 pg mL(-1) of Aβ(1-40). Until now, most quantitative measurements of Aβ in plasma or cerebrospinal fluid have required antibody-based immunoassays. Since quantification of Aβ by immunoassays is highly dependent on the extent of epitope exposure due to aggregation or plasma protein binding, it is difficult to accurately measure the actual concentration of Aβ in plasma. Our diagnostic method based on SRM using a surrogate peptide of Aβ is promising in that actual amounts of total Aβ can be measured regardless of the conformational status of the biomarker.
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104
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Abstract
The complement component receptor 1 gene (CR1), which encodes a type-I transmembrane glycoprotein, has recently been identified as one of the most important risk genes for late-onset Alzheimer's disease (LOAD). In this article, we reviewed the recent evidence concerning the role of CR1 in LOAD. First, we introduced the structure, localization and physiological function of CR1 in humans. Afterward, we summarized the relation of CR1 polymorphisms with LOAD risk. Finally, we discussed the possible impact of CR1 on the pathogenesis of AD including amyloid-β pathology, tauopathy, immune dysfunction and glial-mediated neuroinflammation. We hope that a more comprehensive understanding of the role that CR1 played in AD may lead to the development of novel therapeutics for the prevention and treatment of AD.
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105
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Assarsson A, Hellstrand E, Cabaleiro-Lago C, Linse S. Charge dependent retardation of amyloid β aggregation by hydrophilic proteins. ACS Chem Neurosci 2014; 5:266-74. [PMID: 24475785 DOI: 10.1021/cn400124r] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The aggregation of amyloid β peptides (Aβ) into amyloid fibrils is implicated in the pathology of Alzheimer's disease. In light of the increasing number of proteins reported to retard Aβ fibril formation, we investigated the influence of small hydrophilic model proteins of different charge on Aβ aggregation kinetics and their interaction with Aβ. We followed the amyloid fibril formation of Aβ40 and Aβ42 using thioflavin T fluorescence in the presence of six charge variants of calbindin D9k and single-chain monellin. The formation of fibrils was verified with transmission electron microscopy. We observe retardation of the aggregation process from proteins with net charge +8, +2, -2, and -4, whereas no effect is observed for proteins with net charge of -6 and -8. The single-chain monellin mutant with the highest net charge, scMN+8, has the largest retarding effect on the amyloid fibril formation process, which is noticeably delayed at as low as a 0.01:1 scMN+8 to Aβ40 molar ratio. scMN+8 is also the mutant with the fastest association to Aβ40 as detected by surface plasmon resonance, although all retarding variants of calbindin D9k and single-chain monellin bind to Aβ40.
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Affiliation(s)
- Anna Assarsson
- Divisions
of †Biochemistry and
Structural Biology and ‡Biophysical Chemistry, Lund University, P.O. Box 124, SE 221 00 Lund, Sweden
| | - Erik Hellstrand
- Divisions
of †Biochemistry and
Structural Biology and ‡Biophysical Chemistry, Lund University, P.O. Box 124, SE 221 00 Lund, Sweden
| | - Celia Cabaleiro-Lago
- Divisions
of †Biochemistry and
Structural Biology and ‡Biophysical Chemistry, Lund University, P.O. Box 124, SE 221 00 Lund, Sweden
| | - Sara Linse
- Divisions
of †Biochemistry and
Structural Biology and ‡Biophysical Chemistry, Lund University, P.O. Box 124, SE 221 00 Lund, Sweden
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106
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Osorio RS, Gumb T, Pomara N. Soluble amyloid-β levels and late-life depression. Curr Pharm Des 2014; 20:2547-54. [PMID: 23859552 PMCID: PMC4106797 DOI: 10.2174/13816128113199990502] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Accepted: 07/08/2013] [Indexed: 11/22/2022]
Abstract
Late-Life Major Depression (LLMD) is a complex heterogeneous disorder that has multiple pathophysiological mechanisms such as medical comorbidity, vascular-related factors and Alzheimer's disease (AD). There is an association between LLMD and AD, with LLMD possibly being a risk factor for, or early symptom of AD and vascular dementia. Whether depression is an etiologic risk factor for dementia, or part of the dementia prodrome remains controversial. AD has a long prodromal period with the neuropathologic features of the disease preceding the onset of clinical symptoms by as much as 15-20 years. Clinicopathological studies have provided robust support for the importance of Aβ42 in the pathogenesis of AD, but several other risk factors have also been identified. Given the relationship between Aβ42 and AD, a potential relationship between Aβ42 and LLMD would improve the understanding of the association between LLMD and AD. We reviewed 15 studies that analyzed the relationship between soluble Aβ42 and LLMD. For studies looking at plasma and/or cerebrospinal fluid (CSF) levels of Aβ42, the relationship between LLMD and soluble Aβ42 was equivocal, with some studies finding elevated Aβ42 levels associated with LLMD and others finding the opposite, decreased levels of Aβ42 associated with LLMD. It may be that there is poor reliability in the diagnosis of depression in late life, or variability in the criteria and the scales used, or subtypes of depression in late life such as early vs. late onset depression, vascular-related depression, and preclinical/comorbid depression in AD. The different correlations associated with each of these factors would be causing the inconsistent results for soluble Aβ42 levels in LLMD, but it is also possible that these patterns derive from disease stage-dependent differences in the trajectory of CSF Aβ42 during older age, or changes in neuronal activity or the sleep/wake cycle produced by LLMD that influence Aβ42 dynamics.
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Affiliation(s)
| | | | - Nunzio Pomara
- Center for Brain Health Department of Psychiatry, NYU Center for Brain Health Center of Excellence on Brain Aging and Dementia, 145 E. 32nd Street New York, NY 10016.
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107
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Pesini P, Sarasa M. How close are we to a readily available, clinically reliable blood test for Alzheimer’s disease? Neurodegener Dis Manag 2013. [DOI: 10.2217/nmt.13.48] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
- Pedro Pesini
- Araclon Biotech Ltd, Vía Hispanidad 21, 50009 Zaragoza, Spain
| | - Manuel Sarasa
- Araclon Biotech Ltd, Vía Hispanidad 21, 50009 Zaragoza, Spain
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108
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Shin YG, Hamm L, Murakami S, Buirst K, Buonarati MH, Cox A, Regal K, Hunt KW, Scearce-Levie K, Watts RJ, Liu X. Qualification and application of a liquid chromatography–tandem mass spectrometric method for the determination of human Aβ1-40 and Aβ1-42 peptides in transgenic mouse plasma using micro-elution solid phase extraction. Arch Pharm Res 2013; 37:636-44. [DOI: 10.1007/s12272-013-0215-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Accepted: 07/11/2013] [Indexed: 11/29/2022]
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109
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Choi I, Lee LP. Rapid detection of Aβ aggregation and inhibition by dual functions of gold nanoplasmic particles: catalytic activator and optical reporter. ACS NANO 2013; 7:6268-6277. [PMID: 23777418 DOI: 10.1021/nn402310c] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
One of the primary pathological hallmarks of Alzheimer's diseases (AD) is amyloid-β (Aβ) aggregation and its extracellular accumulation. However, current in vitro Aβ aggregation assays require time-consuming and labor-intensive steps, which delay the process of drug discovery and understanding the mechanism of Aβ induced neurotoxicity. Here, we propose a rapid detection method for studying Aβ aggregation and inhibition under an optimized acidic perturbation condition by dual functions of gold nanoplasmonic particles (GNPs): (1) catalytic activator and (2) optical reporter. Because of roles of GNPs as effective nucleation sites for fast-catalyzing Aβ aggregation and colorimetric optical reporters for tracking Aβ aggregation, we accomplished the fast aggregation assay in less than 1 min by the naked eyes. Our detection method is based on spontaneous clustering of unconjugated (unmodified) GNPs along with the aggregated Aβ network under an aggregation-promoting condition. As a proof-of-concept demonstration, we employed the acidic perturbation permitting rapid cooperative assemblies of GNPs and Aβ peptides via their surface charge modulation. Under the optimized acidic perturbation condition around pH 2 to 3, we characterized the concentration-dependent colorimetric responses for aggregation at physiologically relevant Aβ concentration levels (from 100 μM to 10 nM). We also demonstrated the GNP/acidic condition-based rapid inhibition assay of Aβ aggregation by using well-known binding reagents such as antibody and serum albumin. The proposed methodology can be a powerful alternative method for screening drugs for AD as well as studying molecular biophysics of protein aggregations, and further extended to explore other protein conformational diseases such as neurodegenerative disease.
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Affiliation(s)
- Inhee Choi
- Berkeley Sensor and Actuator Center, Department of Bioengineering, Department of Electrical Engineering and Computer Science, University of California at Berkeley, Berkeley, California 94720, USA
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110
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Roher AE, Cribbs DH, Kim RC, Maarouf CL, Whiteside CM, Kokjohn TA, Daugs ID, Head E, Liebsack C, Serrano G, Belden C, Sabbagh MN, Beach TG. Bapineuzumab alters aβ composition: implications for the amyloid cascade hypothesis and anti-amyloid immunotherapy. PLoS One 2013; 8:e59735. [PMID: 23555764 PMCID: PMC3605408 DOI: 10.1371/journal.pone.0059735] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Accepted: 02/17/2013] [Indexed: 11/23/2022] Open
Abstract
The characteristic neuropathological changes associated with Alzheimer’s disease (AD) and other lines of evidence support the amyloid cascade hypothesis. Viewing amyloid deposits as the prime instigator of dementia has now led to clinical trials of multiple strategies to remove or prevent their formation. We performed neuropathological and biochemical assessments of 3 subjects treated with bapineuzumab infusions. Histological analyses were conducted to quantify amyloid plaque densities, Braak stages and the extent of cerebral amyloid angiopathy (CAA). Amyloid-β (Aβ) species in frontal and temporal lobe samples were quantified by ELISA. Western blots of amyloid-β precursor protein (AβPP) and its C-terminal (CT) fragments as well as tau species were performed. Bapineuzumab-treated (Bapi-AD) subjects were compared to non-immunized age-matched subjects with AD (NI-AD) and non-demented control (NDC) cases. Our study revealed that Bapi-AD subjects exhibited overall amyloid plaque densities similar to those of NI-AD cases. In addition, CAA was moderate to severe in NI-AD and Bapi-AD patients. Although histologically-demonstrable leptomeningeal, cerebrovascular and neuroparenchymal-amyloid densities all appeared unaffected by treatment, Aβ peptide profiles were significantly altered in Bapi-AD subjects. There was a trend for reduction in total Aβ42 levels as well as an increase in Aβ40 which led to a corresponding significant decrease in Aβ42:Aβ40 ratio in comparison to NI-AD subjects. There were no differences in the levels of AβPP, CT99 and CT83 or tau species between Bapi-AD and NI-AD subjects. The remarkable alteration in Aβ profiles reveals a dynamic amyloid production in which removal and depositional processes were apparently perturbed by bapineuzumab therapy. Despite the alteration in biochemical composition, all 3 immunized subjects exhibited continued cognitive decline.
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Affiliation(s)
- Alex E Roher
- The Longtine Center for Neurodegenerative Biochemistry, Banner Sun Health Research Institute, Sun City, Arizona, United States of America.
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111
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Toledo JB, Shaw LM, Trojanowski JQ. Plasma amyloid beta measurements - a desired but elusive Alzheimer's disease biomarker. ALZHEIMERS RESEARCH & THERAPY 2013; 5:8. [PMID: 23470128 PMCID: PMC3706955 DOI: 10.1186/alzrt162] [Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Cerebrospinal fluid and positron emission tomography biomarkers accurately predict an underlying Alzheimer's disease (AD) pathology; however, they represent either invasive or expensive diagnostic tools. Therefore, a blood-based biomarker like plasma amyloid beta (Aβ) that could correlate with the underlying AD pathology and serve as a prognostic biomarker or an AD screening strategy is urgently needed as a cost-effective and non-invasive diagnostic tool. In this paper we review the demographic, biologic, genetic and technical aspects that affect plasma Aβ levels. Findings of cross-sectional and longitudinal studies of plasma Aβ, including autosomal dominant AD cases, sporadic AD cases, Down syndrome cases and population studies, are also discussed. Finally, we review the association between cerebrovascular disease and Aβ plasma levels and the responses observed in clinical trials. Based on our review of the current literature on plasma Aβ, we conclude that further clinical research and assay development are needed before measures of plasma Aβ can be interpreted so they can be applied as trait, risk or state biomarkers for AD.
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Affiliation(s)
- Jon B Toledo
- Department of Pathology and Laboratory Medicine, Institute on Aging, Center for Neurodegenerative Disease Research, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Leslie M Shaw
- Department of Pathology and Laboratory Medicine, Institute on Aging, Center for Neurodegenerative Disease Research, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - John Q Trojanowski
- Department of Pathology and Laboratory Medicine, Institute on Aging, Center for Neurodegenerative Disease Research, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
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112
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Kiko T, Nakagawa K, Satoh A, Tsuduki T, Furukawa K, Arai H, Miyazawa T. Amyloid β levels in human red blood cells. PLoS One 2012; 7:e49620. [PMID: 23166730 PMCID: PMC3499416 DOI: 10.1371/journal.pone.0049620] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Accepted: 10/10/2012] [Indexed: 11/18/2022] Open
Abstract
UNLABELLED Amyloid β-peptide (Aβ) is hypothesized to play a key role by oxidatively impairing the capacity of red blood cells (RBCs) to deliver oxygen to the brain. These processes are implicated in the pathogenesis of Alzheimer's disease (AD). Although plasma Aβ has been investigated thoroughly, the presence and distribution of Aβ in human RBCs are still unclear. In this study, we quantitated Aβ40 and Aβ42 in human RBCs with ELISA assays, and provided evidence that significant amounts of Aβ could be detected in RBCs and that the RBC Aβ levels increased with aging. The RBC Aβ levels increased with aging. On the other hand, providing an antioxidant supplement (astaxanthin, a polar carotenoid) to humans was found to decrease RBC Aβ as well as oxidative stress marker levels. These results suggest that plasma Aβ40 and Aβ42 bind to RBCs (possibly with aging), implying a pathogenic role of RBC Aβ. Moreover, the data indicate that RBC Aβ40 and Aβ42 may constitute biomarkers of AD. As a preventive strategy, therapeutic application of astaxanthin as an Aβ-lowering agent in RBCs could be considered as a possible anti-dementia agent. TRIAL REGISTRATION Controlled-Trials.com ISRCTN42483402.
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Affiliation(s)
- Takehiro Kiko
- Food and Biodynamic Chemistry Laboratory, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Kiyotaka Nakagawa
- Food and Biodynamic Chemistry Laboratory, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Akira Satoh
- Life Science Institute, Yamaha Motor Company, Ltd., Shizuoka, Japan
| | - Tsuyoshi Tsuduki
- Laboratory of Food and Biomolecular Science, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Katsutoshi Furukawa
- Department of Geriatrics and Gerontology, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Hiroyuki Arai
- Department of Geriatrics and Gerontology, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Teruo Miyazawa
- Food and Biodynamic Chemistry Laboratory, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
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113
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Oma S, Mawatari S, Saito K, Wakana C, Tsuboi Y, Yamada T, Fujino T. Changes in phospholipid composition of erythrocyte membrane in Alzheimer's disease. Dement Geriatr Cogn Dis Extra 2012; 2:298-303. [PMID: 22962553 PMCID: PMC3435527 DOI: 10.1159/000341603] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Background There are several reports indicating a decrease of ethanolamine plasmalogen (pl-PE) in brain tissues and in serum of patients with Alzheimer's disease (AD). The present study aimed to examine the composition of erythrocyte phospholipids including pl-PE in patients with AD. Method A high-performance liquid chromatography (HPLC) method that can separate intact plasmalogens and all other phospholipid classes by a single chromatographic run was used. Results The ratios of pl-PE, phosphatidylethanolamine (PE) and phosphatidylserine (PS) to sphingomyelin were low as compared to those of the age-matched controls. Conclusion These changes in erythrocyte phospholipids may reflect changes induced by oxidative stress, indicating the presence of high oxidative stress in the peripheral blood of AD patients.
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Affiliation(s)
- Shinji Oma
- Department of Neurology, Fukuoka University School of Medicine, Fukuoka, Japan
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114
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Abstract
Changes in expression and secretion levels of cystatin C (CysC) in the brain in various neurological disorders and in animal models of neurodegeneration underscore a role for CysC in these conditions. A polymorphism in the CysC gene (CST3) is linked to increased risk for Alzheimer's disease (AD). AD pathology is characterized by deposition of oligomeric and fibrillar forms of amyloid β (Aβ) in the neuropil and cerebral vessel walls, neurofibrillary tangles composed mainly of hyperphosphorylated tau, and neurodegeneration. The implication of CysC in AD was initially suggested by its co-localization with Aβ in amyloid-laden vascular walls, and in senile plaque cores of amyloid in the brains of patients with AD, Down's syndrome, hereditary cerebral hemorrhage with amyloidosis, Dutch type (HCHWA-D), and cerebral infarction. CysC also co-localizes with Aβ amyloid deposits in the brains of non-demented aged individuals. Multiple lines of research show that CysC plays protective roles in AD. In vitro studies have shown that CysC binds Aβ and inhibits Aβ oligomerization and fibril formation. In vivo results from the brains and plasma of Aβ-depositing transgenic mice confirmed the association of CysC with the soluble, non-pathological form of Aβ and the inhibition of Aβ plaques formation. The association of CysC with Aβ was also found in brain and in cerebrospinal fluid (CSF) from AD patients and non-demented control individuals. Moreover, in vitro results showed that CysC protects neuronal cells from a variety of insults that may cause cell death, including cell death induced by oligomeric and fibrillar Aβ. These data suggest that the reduced levels of CysC manifested in AD contribute to increased neuronal vulnerability and impaired neuronal ability to prevent neurodegeneration. This review elaborates on the neuroprotective roles of CysC in AD and the clinical relevance of this protein as a therapeutic agent.
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Affiliation(s)
- Gurjinder Kaur
- Departments of Psychiatry, Biochemistry, and Molecular Pharmacology, Center for Dementia Research, Nathan S. Kline Institute, New York University School of Medicine, Orangeburg NY, USA
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115
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Stanyon HF, Viles JH. Human serum albumin can regulate amyloid-β peptide fiber growth in the brain interstitium: implications for Alzheimer disease. J Biol Chem 2012; 287:28163-8. [PMID: 22718756 DOI: 10.1074/jbc.c112.360800] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Alzheimer disease is a neurodegenerative disorder characterized by extracellular accumulation of amyloid-β peptide (Aβ) in the brain interstitium. Human serum albumin (HSA) binds 95% of Aβ in blood plasma and is thought to inhibit plaque formation in peripheral tissue. However, the role of albumin in binding Aβ in the cerebrospinal fluid has been largely overlooked. Here we investigate the effect of HSA on both Aβ(1-40) and Aβ(1-42) fibril growth. We show that at micromolar cerebrospinal fluid levels, HSA inhibits the kinetics of Aβ fibrillization, significantly increasing the lag time and decreasing the total amount of fibrils produced. Furthermore, we show that the amount of amyloid fibers generated directly correlates to the proportion of Aβ not competitively bound to albumin. Our observations suggest a significant role for HSA regulating Aβ fibril growth in the brain interstitium.
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Affiliation(s)
- Helen F Stanyon
- School of Biological and Chemical Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS, United Kingdom
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116
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Finn TE, Nunez AC, Sunde M, Easterbrook-Smith SB. Serum albumin prevents protein aggregation and amyloid formation and retains chaperone-like activity in the presence of physiological ligands. J Biol Chem 2012; 287:21530-40. [PMID: 22549788 DOI: 10.1074/jbc.m112.372961] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Although serum albumin has an established function as a transport protein, evidence is emerging that serum albumin may also have a role as a molecular chaperone. Using established techniques to characterize chaperone interactions, this study demonstrates that bovine serum albumin: 1) preferentially binds stressed over unstressed client proteins; 2) forms stable, soluble, high molecular weight complexes with stressed client proteins; 3) reduces the aggregation of client proteins when it is present at physiological levels; and 4) inhibits amyloid formation by both WT and L55P transthyretin. Although the antiaggregatory effect of serum albumin is maintained in the presence of physiological levels of Ca(2+) and Cu(2+), the presence of free fatty acids significantly alters this activity: stabilizing serum albumin at normal levels but diminishing chaperone-like activity at high concentrations. Moreover, here it is shown that depletion of albumin from human plasma leads to a significant increase in aggregation under physiologically relevant heat and shear stresses. This study demonstrates that serum albumin possesses chaperone-like properties and that this activity is maintained under a number of physiologically relevant conditions.
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Affiliation(s)
- Thomas E Finn
- School of Molecular Bioscience and Discipline of Pharmacology, The University of Sydney, Sydney, New South Wales 2006, Australia
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117
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Watanabe KI, Ishikawa C, Kuwahara H, Sato K, Komuro S, Nakagawa T, Nomura N, Watanabe S, Yabuki M. A new methodology for simultaneous quantification of total-Aβ, Aβx-38, Aβx-40, and Aβx-42 by column-switching LC/MS/MS. Anal Bioanal Chem 2011; 402:2033-42. [PMID: 22200927 DOI: 10.1007/s00216-011-5648-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Revised: 12/07/2011] [Accepted: 12/07/2011] [Indexed: 10/14/2022]
Abstract
This article details the development of a novel method that overcomes the drawbacks of sandwich ELISA (sELISA) and allows reliable evaluation of simultaneous quantification of the amyloid (Aβ)-peptides, total-Aβ, Aβx-38, Aβx-40, and Aβx-42, in rat brain by optimized sample purification and column-switching liquid chromatographic-tandem mass spectrometry (LC/MS/MS). This method provides accurate analyses of total-Aβ, Aβx-38, Aβx-40, and Aβx-42 with a linear calibration range between 0.05 and 45 ng/mL. Verification for accuracy and precision of biological samples were determined by a standard addition and recovery test, spiked with synthetic Aβ1-38, Aβ1-40, and Aβ1-42 into the rat brain homogenate. This method showed <20% relative error and relative standard deviation, indicating high reproducibility and reliability. The brain concentrations of total-Aβ, Aβx-38, Aβx-40, and Aβx-42 after oral administration of flurbiprofen in rats were measured by this method. Aβx-42 concentrations (4.57 ± 0.69 ng/g) in rats administered flurbiprofen were lower than those in untreated rats (6.48 ± 0.93 ng/g). This was consistent with several reports demonstrating that NSAIDs reduced the generation of Aβ. We report here a method that allows not only the quantification of specific molecular species of Aβ but also simultaneous quantification of total-Aβ, Aβx-38, Aβx-40, and Aβx-42, thus overcoming the drawbacks of sELISA.
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Affiliation(s)
- Ken-ichi Watanabe
- Pharmacokinetics Research Laboratory, Dainippon Sumitomo Pharmaceutical Co., Ltd., Suita-shi, Osaka, Japan.
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118
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Funke SA. Detection of Soluble Amyloid-β Oligomers and Insoluble High-Molecular-Weight Particles in CSF: Development of Methods with Potential for Diagnosis and Therapy Monitoring of Alzheimer's Disease. Int J Alzheimers Dis 2011; 2011:151645. [PMID: 22114742 PMCID: PMC3216303 DOI: 10.4061/2011/151645] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Accepted: 09/11/2011] [Indexed: 11/20/2022] Open
Abstract
The diagnosis of probable Alzheimer's disease (AD) can be established premortem based on clinical criteria like neuropsychological tests. Post mortem, specific neuropathological changes like amyloid plaques define AD. However, the standard criteria based on medical history and mental status examinations do not take into account the long preclinical features of the disease, and a biomarker for improved diagnosis of AD is urgently needed. In a large number of studies, amyloid-β (Aβ) monomer concentrations in CSF of AD patients are consistently and significantly reduced when compared to healthy controls. Therefore, monomeric Aβ in CSF was suggested to be a helpful biomarker for the diagnosis of preclinical AD. However, not the monomeric form, but Aβ oligomers have been shown to be the toxic species in AD pathology, and their quantification and characterization could facilitate AD diagnosis and therapy monitoring. Here, we review the current status of assay development to reliably and routinely detect Aβ oligomers and high-molecular-weight particles in CSF.
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119
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Ma SL, Lam LCW. Panel of Genetic Variations as a Potential Non-invasive Biomarker for Early Diagnosis of Alzheimer's Disease. CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE 2011; 9:54-66. [PMID: 23429712 PMCID: PMC3569084 DOI: 10.9758/cpn.2011.9.2.54] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Revised: 05/06/2011] [Accepted: 05/23/2011] [Indexed: 01/05/2023]
Abstract
Alzheimer's disease (AD) is the most prevalent form of dementia. Biomarkers such as levels of amyloid beta (Aβ) in cerebrospinal fluid and ApoE genotyping were suggested for the diagnosis of AD, however, the result is either non-conclusive or with invasive procedure. Genome-wide association studies (GWASs) for AD suggested single nucleotide polymorphisms (SNPs) in many genes are associated with the risk of AD, but each only contributed with small effect to the disease. By incorporating a panel of established genetic susceptibility factors, the risk of an individual in getting AD could be better estimated. Further research will be required to reveal if adding to the current well-developed clinical diagnosis protocol, the accuracy and specificity of diagnosis of AD would be greatly improved and if this might also be beneficial in identifying pre-symptomatic AD patients for early diagnosis and intervention of the disease.
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Affiliation(s)
- Suk Ling Ma
- Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA. ; Department of Psychiatry, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong
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120
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Kokjohn TA, Van Vickle GD, Maarouf CL, Kalback WM, Hunter JM, Daugs ID, Luehrs DC, Lopez J, Brune D, Sue LI, Beach TG, Castaño EM, Roher AE. Chemical characterization of pro-inflammatory amyloid-beta peptides in human atherosclerotic lesions and platelets. Biochim Biophys Acta Mol Basis Dis 2011; 1812:1508-14. [PMID: 21784149 DOI: 10.1016/j.bbadis.2011.07.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Revised: 06/27/2011] [Accepted: 07/05/2011] [Indexed: 01/23/2023]
Abstract
Amyloid-β (Aβ) peptides are intimately involved in the inflammatory pathology of atherosclerotic vascular disease (AVD) and Alzheimer's disease (AD). Although substantial amounts of these peptides are produced in the periphery, their role and significance to vascular disease outside the brain requires further investigation. Amyloid-β peptides present in the walls of human aorta atherosclerotic lesions as well as activated and non-activated human platelets were isolated using sequential size-exclusion columns and HPLC reverse-phase methods. The Aβ peptide isolates were quantified by ELISA and structurally analyzed using MALDI-TOF mass spectrometry procedures. Our experiments revealed that both aorta and platelets contained Aβ peptides, predominately Aβ40. The source of the Aβ pool in aortic atherosclerosis lesions is probably the activated platelets and/or vascular wall cells expressing APP/PN2. Significant levels of Aβ42 are present in the plasma, suggesting that this reservoir makes a minor contribution to atherosclerotic plaques. Our data reveal that although aortic atherosclerosis and AD cerebrovascular amyloidosis exhibit clearly divergent end-stage manifestations, both vascular diseases share some key pathophysiological promoting elements and pathways. Whether they happen to be deposited in vessels of the central nervous system or atherosclerotic plaques in the periphery, Aβ peptides may promote and perhaps synergize chronic inflammatory processes which culminate in the degeneration, malfunction and ultimate destruction of arterial walls.
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Affiliation(s)
- Tyler A Kokjohn
- The Longtine Center for Neurodegenerative Biochemistry, Banner Sun Health Research Institute, Sun City, AZ 85351, USA
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121
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CLU, CR1 and PICALM genes associate with Alzheimer's-related senile plaques. ALZHEIMERS RESEARCH & THERAPY 2011; 3:12. [PMID: 21466683 PMCID: PMC3226274 DOI: 10.1186/alzrt71] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Revised: 03/22/2011] [Accepted: 04/05/2011] [Indexed: 02/03/2023]
Abstract
INTRODUCTION APOE is the strongest risk gene for sporadic Alzheimer's disease (AD) so far. Recent genome wide association studies found links for sporadic AD with CLU and CR1 involved in Aβ clearance, and PICALM affecting intracellular trafficking. METHODS We investigated the associations of senile plaques (SP) and neurofibrillary tangles (NFT) with the proposed risk genes and APOE, in the Tampere Autopsy Study (TASTY) series (603 cases), a sample of the general population (0 to 97 yrs), who died out-of-hospital. RESULTS Age and the APOEε4 allele associated strongly with all phenotypes of SP, as expected. In age and APOEε4 adjusted analyses, compared to the most common homozygous genotype, burnt out SP were more common among carriers of the C-allele of CLU, whereas the T-allele of PICALM and C-allele of CR1 were linked with lower SP coverage. We found no significant associations between any of the genetic variants and NFT. CONCLUSIONS Marginal effects from CLU, CR1 and PICALM suggest that these genes have minimal effects on the development of AD lesions.
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122
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Amyloid β-induced erythrocytic damage and its attenuation by carotenoids. FEBS Lett 2011; 585:1249-54. [PMID: 21459092 DOI: 10.1016/j.febslet.2011.03.060] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Revised: 03/23/2011] [Accepted: 03/28/2011] [Indexed: 11/22/2022]
Abstract
The presence of amyloid β-peptide (Aβ) in human blood has recently been established, and it has been hypothesized that Aβ readily contacts red blood cells (RBC) and oxidatively impairs RBC functions. In this study, we conducted in vitro and in vivo studies, which provide evidence that Aβ induces oxidative injury to RBC by binding to them, causing RBC phospholipid peroxidation and diminishing RBC endogenous carotenoids, especially xanthophylls. This type of damage is likely to injure the vasculature, potentially reducing oxygen delivery to the brain and facilitating Alzheimer's disease (AD). As a preventive strategy, because the Aβ-induced RBC damage could be attenuated by treatment of RBC with xanthophylls, we suggest that xanthophylls may contribute to the prevention of AD.
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123
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Aluminum enhances the toxic effects of amyloid β-peptide on cell membranes and a molecular model. MONATSHEFTE FUR CHEMIE 2011. [DOI: 10.1007/s00706-011-0471-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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124
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Schieb H, Spitzer P, Riess V, Wiltfang J, Klafki HW. A method to prevent cross contamination during 2-DE by β-amyloid peptides. Proteomics 2011; 10:3539-43. [PMID: 20827735 DOI: 10.1002/pmic.201000227] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A method for the efficient decontamination of aluminium oxide ceramic 2-DE focusing trays from β-amyloid peptides (Aβ) is reported. As these contaminations were resistant to the standard cleaning procedures, additional harsh cleaning steps were necessary for their efficient removal. Our observations suggest that specific surface properties affect the degree of adsorption of the Aβ-peptides. "Surface catalysed amyloid aggregation" in the aluminium oxide ceramic trays is proposed as a possible underlying mechanism for the occurrence of proteinase K-resistant forms of Aβ.
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Affiliation(s)
- Heinke Schieb
- Department of Psychiatry and Psychotherapy, University of Duisburg-Essen, LVR-Klinikum, Essen, Germany
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125
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Seppälä TT, Herukka SK, Hänninen T, Tervo S, Hallikainen M, Soininen H, Pirttilä T. Plasma Abeta42 and Abeta40 as markers of cognitive change in follow-up: a prospective, longitudinal, population-based cohort study. J Neurol Neurosurg Psychiatry 2010; 81:1123-7. [PMID: 20478847 PMCID: PMC2976614 DOI: 10.1136/jnnp.2010.205757] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
BACKGROUND Single measurements of plasma Aβ are not useful in the diagnostics of Alzheimer's disease (AD). However, changes in plasma Aβ levels during repeated testing may be helpful in the prediction and evaluation of progression of the incipient AD or mild cognitive impairment. OBJECTIVE To examine the relation of baseline and serial plasma Aβ levels to cognitive change in follow-up. METHODS 269 subjects (52 cognitively impaired and 217 controls) from a population-based cohort were clinically followed up from 3 to 6 years. Serial plasma samples were available from 70 subjects who were followed up for 3 years and 43 subjects followed for 6 years. The plasma Aβ levels were measured using ELISA. RESULTS Subjects who declined cognitively during the follow-up had lower levels of plasma Aβ42 at the baseline. Plasma Aβ42 and the Aβ42/Aβ40 ratio decreased (-2.4 pg/ml for Aβ42 in 6 years) in those who declined in follow-up, whereas Aβ42 and the Aβ42/Aβ40 ratio increased in the subjects who remained cognitively stable or improved in follow-up. Subjects using acetylsalicylic acid, dipyridamole, antidiabetic or anticoagulant drugs as well as subjects with coronary heart disease had higher levels of Aβ40. CONCLUSIONS Low or decreasing plasma Aβ42 during the follow-up is associated with cognitive decline. Serial measurement of plasma Aβ42 may be useful in the detection of the subjects who are at risk for cognitive decline.
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Affiliation(s)
- T T Seppälä
- Department of Neurology, Kuopio University Hospital, University of Eastern Finland, Kuopio, Finland
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126
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Zhang Q, Yu JT, Zhu QX, Zhang W, Wu ZC, Miao D, Tan L. Complement receptor 1 polymorphisms and risk of late-onset Alzheimer's disease. Brain Res 2010; 1348:216-21. [DOI: 10.1016/j.brainres.2010.06.018] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2010] [Revised: 06/06/2010] [Accepted: 06/07/2010] [Indexed: 11/15/2022]
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127
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Anoop A, Singh PK, Jacob RS, Maji SK. CSF Biomarkers for Alzheimer's Disease Diagnosis. Int J Alzheimers Dis 2010; 2010. [PMID: 20721349 PMCID: PMC2915796 DOI: 10.4061/2010/606802] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Accepted: 04/27/2010] [Indexed: 01/12/2023] Open
Abstract
Alzheimer's disease (AD) is the most common form of dementia that affects several million people worldwide. The major neuropathological hallmarks of AD are the presence of extracellular amyloid plaques that are composed of Aβ40 and Aβ42 and intracellular neurofibrillary tangles (NFT), which is composed of hyperphosphorylated protein Tau. While the amyloid plaques and NFT could define the disease progression involving neuronal loss and dysfunction, significant cognitive decline occurs before their appearance. Although significant advances in neuroimaging techniques provide the structure and physiology of brain of AD cases, the biomarker studies based on cerebrospinal fluid (CSF) and plasma represent the most direct and convenient means to study the disease progression. Biomarkers are useful in detecting the preclinical as well as symptomatic stages of AD. In this paper, we discuss the recent advancements of various biomarkers with particular emphasis on CSF biomarkers for monitoring the early development of AD before significant cognitive dysfunction.
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Affiliation(s)
- A Anoop
- Department of Biosciences and Bioengineering, IIT Bombay, Powai, Mumbai 400076, India
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128
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Jorquera JI. Relevance of quantitative measurements of anti-Aβ antibodies in therapeutic intravenous immunoglobulin using synthetic peptides. Int Immunopharmacol 2010; 10:373-4; author reply 375-6. [DOI: 10.1016/j.intimp.2009.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2009] [Accepted: 12/08/2009] [Indexed: 11/25/2022]
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129
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Milojevic J, Raditsis A, Melacini G. Human serum albumin inhibits Abeta fibrillization through a "monomer-competitor" mechanism. Biophys J 2010; 97:2585-94. [PMID: 19883602 DOI: 10.1016/j.bpj.2009.08.028] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2009] [Revised: 08/14/2009] [Accepted: 08/18/2009] [Indexed: 11/18/2022] Open
Abstract
Human serum albumin (HSA) is not only a fatty acid and drug carrier protein, it is also a potent inhibitor of Abeta self-association in plasma. However, the mechanism underlying the inhibition of Abeta fibrillization by HSA is still not fully understood. We therefore investigated the Abeta-HSA system using a combined experimental strategy based on saturation transfer difference (STD) NMR and intrinsic albumin fluorescence experiments on three Abeta peptides with different aggregation propensities (i.e., Abeta(12-28), Abeta(1-40), and Abeta(1-42)). Our data consistently show that albumin selectively binds to cross-beta-structured Abeta oligomers as opposed to Abeta monomers. The HSA/Abeta oligomer complexes have K(D) values in the micromolar to submicromolar range and compete with the further addition of Abeta monomers to the Abeta assemblies, thus inhibiting fibril growth ("monomer competitor" model). Other putative mechanisms, according to which albumin acts as a "monomer stabilizer" or a "dissociation catalyst", are not supported by our data, thus resolving previous discrepancies in the literature regarding Abeta-HSA interactions. In addition, the model and the experimental approaches proposed here are anticipated to have broad relevance for the characterization of other systems that involve amyloidogenic peptides and oligomerization inhibitors.
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Affiliation(s)
- Julijana Milojevic
- Department of Chemistry and Chemical Biology, and Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
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130
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Depression and plasma amyloid beta peptides in the elderly with and without the apolipoprotein E4 allele. Alzheimer Dis Assoc Disord 2010; 23:238-44. [PMID: 19812466 DOI: 10.1097/wad.0b013e31819cb3ac] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Depression associated with low plasma amyloid-beta peptide 42 (Abeta42) leading to a high ratio of Abeta40/Abeta42, a biomarker of Alzheimer disease (AD), may represent a unique depression subtype. The relationship between low plasma Abeta42 in depression and the major risk factor of AD, apolipoprotein E4 (ApoE4), is unknown. With the goal of clarifying this relationship, we analyzed 1060 homebound elders with ApoE characterization and depression status in a cross-sectional study. Plasma Abeta40 and Abeta42 were measured, and cognition were evaluated. In the absence of the ApoE4 allele, depressed subjects had lower plasma Abeta42 [median (Q1, Q3): 17.1 (11.6, 27.8) vs. 20.2 (12.9, 32.9) pg/mL, P=0.006], a higher Abeta40/Abeta42 ratio [median (Q1, Q3): 7.1 (4.6, 11.3) vs. 6.9 (3.4, 9.7), P=0.03], and lower cognitive function (mean+/-SD of Mini-Mental State Examination: 24.5+/-3.1 vs. 25.5+/-3.3, P<0.0001) than those without depression. In contrast, these relationships were not observed in the presence of ApoE4. Instead, regardless the depression status ApoE4 carriers had lower plasma Abeta42 and a higher Abeta40/Abeta42 ratio than non-ApoE4 carriers. Using multivariate logistic regression, it was found that depression was not associated with ApoE4 allele, but with the interaction between plasma Abeta42 and ApoE4 (odds ratio=3.94, 95% confidence interval=1.50, 10.33, P=0.005), denoting low plasma Abeta42 in the absence of ApoE4. Both ApoE4 carriers and non-ApoE4 carriers with depression had lower Abeta42 and a higher Abeta40/Abeta42 ratio in plasma compared with non-ApoE4 carriers without depression in the homebound elderly. As a combination of low plasma Abeta42 and high plasma Abeta40 has been shown to increase the risk of AD in 2 large cohort studies, amyloid-associated depression shown in this study may suggest a risk factor of AD in the absence of ApoE4.
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131
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Rózga M, Bal W. The Cu(II)/Aβ/Human Serum Albumin Model of Control Mechanism for Copper-Related Amyloid Neurotoxicity. Chem Res Toxicol 2009; 23:298-308. [DOI: 10.1021/tx900358j] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Małgorzata Rózga
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106 Warsaw, Poland, and Central Institute for Labour Protection, National Research Institute, Czerniakowska 16, 00-701 Warsaw, Poland
| | - Wojciech Bal
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106 Warsaw, Poland, and Central Institute for Labour Protection, National Research Institute, Czerniakowska 16, 00-701 Warsaw, Poland
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Marcello A, Wirths O, Schneider-Axmann T, Degerman-Gunnarsson M, Lannfelt L, Bayer TA. Reduced levels of IgM autoantibodies against N-truncated pyroglutamate Aβ in plasma of patients with Alzheimer's disease. Neurobiol Aging 2009; 32:1379-87. [PMID: 19781815 DOI: 10.1016/j.neurobiolaging.2009.08.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2009] [Revised: 08/10/2009] [Accepted: 08/25/2009] [Indexed: 12/23/2022]
Abstract
In the present work, we investigated the level of IgM autoantibodies directed against different Aβ epitopes as potential diagnostic biomarker for Alzheimer's disease (AD). Anti-Aβ autoantibody levels were measured in 75 plasma samples from patients with AD, individuals with mild cognitive impairment (MCI), and healthy age- and sex-matched controls (HC). To validate the presence of anti-Aβ IgMs, pooled plasma samples were subjected to gel-filtration analysis. The mean level of pGluAβ-IgM (N-terminal truncated starting at position three with pyroglutamate) was significantly decreased in AD patients as compared to HC. In the group of MCI patients there was a significant positive correlation between pGluAβ-IgM and cognitive decline analyzed by MMSE (rho = 0.58, d.f. = 13, p = 0.022). These observations indicate that the level of IgM autoantibodies against pGluAβ is a promising plasma biomarker for AD and correlates with the cognitive status of individuals at risk to develop AD.
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Affiliation(s)
- Andrea Marcello
- University Medicine of Goettingen, Department of Psychiatry, Goettingen, Germany
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133
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Genome-wide association study identifies variants at CLU and CR1 associated with Alzheimer's disease. Nat Genet 2009; 41:1094-9. [PMID: 19734903 DOI: 10.1038/ng.439] [Citation(s) in RCA: 1845] [Impact Index Per Article: 123.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Accepted: 07/31/2009] [Indexed: 12/11/2022]
Abstract
The gene encoding apolipoprotein E (APOE) on chromosome 19 is the only confirmed susceptibility locus for late-onset Alzheimer's disease. To identify other risk loci, we conducted a large genome-wide association study of 2,032 individuals from France with Alzheimer's disease (cases) and 5,328 controls. Markers outside APOE with suggestive evidence of association (P < 10(-5)) were examined in collections from Belgium, Finland, Italy and Spain totaling 3,978 Alzheimer's disease cases and 3,297 controls. Two loci gave replicated evidence of association: one within CLU (also called APOJ), encoding clusterin or apolipoprotein J, on chromosome 8 (rs11136000, OR = 0.86, 95% CI 0.81-0.90, P = 7.5 x 10(-9) for combined data) and the other within CR1, encoding the complement component (3b/4b) receptor 1, on chromosome 1 (rs6656401, OR = 1.21, 95% CI 1.14-1.29, P = 3.7 x 10(-9) for combined data). Previous biological studies support roles of CLU and CR1 in the clearance of beta amyloid (Abeta) peptide, the principal constituent of amyloid plaques, which are one of the major brain lesions of individuals with Alzheimer's disease.
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134
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Marcello A, Wirths O, Schneider-Axmann T, Degerman-Gunnarsson M, Lannfelt L, Bayer TA. Circulating immune complexes of Abeta and IgM in plasma of patients with Alzheimer's disease. J Neural Transm (Vienna) 2009; 116:913-20. [PMID: 19415450 PMCID: PMC2700872 DOI: 10.1007/s00702-009-0224-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2009] [Accepted: 03/21/2009] [Indexed: 01/01/2023]
Abstract
It has previously been shown that immune complexes (IC) of a given biomarker with class M immunoglobulins (IgM) provide better performances compared to the unbound biomarker in a number of cancer entities. In the present work, we investigated IC of IgM-Aβ as a potential biomarker for Alzheimer’s disease (AD). Aβ–IgM concentration has been measured in 75 plasma samples from patients with AD, individuals with mild cognitive impairment (MCI), and healthy age- and sex-matched controls (HC). To characterize the fractions associated with Aβ, pooled plasma samples were subjected to gel-filtration analysis. Size-separated fractions were analyzed for the presence of Aβ using a sandwich ELISA assay. A strong reactivity was observed in the high molecular weight IgM (>500 kDa) and 150 kDa (IgG) fractions indicating that blood Aβ is strongly associated with antibodies. Using an ELISA assay detecting Aβ–IgM complexes, we observed that high levels of Aβ–IgMs were detectable in HC and MCI patients; however, there was no significant difference to the AD group.
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Affiliation(s)
- Andrea Marcello
- Department of Psychiatry, University Medicine Goettingen, Göttingen 37075, Germany
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135
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Clearance mechanisms of Alzheimer's amyloid-beta peptide: implications for therapeutic design and diagnostic tests. Mol Psychiatry 2009; 14:469-86. [PMID: 18794889 DOI: 10.1038/mp.2008.96] [Citation(s) in RCA: 172] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Currently, the 'amyloid hypothesis' is the most widely accepted explanation for the pathogenesis of Alzheimer's disease (AD). According to this hypothesis, altered metabolism of the amyloid-beta (Abeta) peptide is central to the pathological cascade involved in the pathogenesis of AD. Although Abeta is produced by almost every cell in the body, a physiological function for the peptide has not been determined, and the pathways by which Abeta leads to cognitive dysfunction and cell death are unclear. Numerous therapeutic approaches that target the production, toxicity and removal of Abeta are being developed worldwide. Although therapeutic treatment for AD may be imminent, the value and effectiveness of such treatment are largely dependent on early diagnosis of the disease. This review summarizes current knowledge of Abeta clearance, transport and degradation, and evaluates the use of such information in the development of diagnostic tools. The conflicting results of plasma Abeta ELISAs are discussed, as are the more promising results of Abeta imaging by positron emission tomography. Current knowledge of Abeta-binding proteins and Abeta-degrading enzymes is analysed in the context of a potential therapy for AD. Transport across the blood-brain barrier by the receptor for advanced glycation end products and efflux via the multi-ligand lipoprotein receptor LRP-1 is also reviewed. Enhancing clearance and degradation of Abeta remains an attractive therapeutic strategy, and improved understanding of Abeta clearance may lead to advances in diagnostics and interventions designed to prevent or delay the onset of AD.
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136
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Reyes Barcelo AA, Gonzalez-Velasquez FJ, Moss MA. Soluble aggregates of the amyloid-beta peptide are trapped by serum albumin to enhance amyloid-beta activation of endothelial cells. J Biol Eng 2009; 3:5. [PMID: 19397812 PMCID: PMC2683804 DOI: 10.1186/1754-1611-3-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2008] [Accepted: 04/27/2009] [Indexed: 11/14/2022] Open
Abstract
Background Self-assembly of the amyloid-β peptide (Aβ) has been implicated in the pathogenesis of Alzheimer's disease (AD). As a result, synthetic molecules capable of inhibiting Aβ self-assembly could serve as therapeutic agents and endogenous molecules that modulate Aβ self-assembly may influence disease progression. However, increasing evidence implicating a principal pathogenic role for small soluble Aβ aggregates warns that inhibition at intermediate stages of Aβ self-assembly may prove detrimental. Here, we explore the inhibition of Aβ1–40 self-assembly by serum albumin, the most abundant plasma protein, and the influence of this inhibition on Aβ1–40 activation of endothelial cells for monocyte adhesion. Results It is demonstrated that serum albumin is capable of inhibiting in a dose-dependent manner both the formation of Aβ1–40 aggregates from monomeric peptide and the ongoing growth of Aβ1–40 fibrils. Inhibition of fibrillar Aβ1–40 aggregate growth is observed at substoichiometric concentrations, suggesting that serum albumin recognizes aggregated forms of the peptide to prevent monomer addition. Inhibition of Aβ1–40 monomer aggregation is observed down to stoichiometric ratios with partial inhibition leading to an increase in the population of small soluble aggregates. Such partial inhibition of Aβ1–40 aggregation leads to an increase in the ability of resulting aggregates to activate endothelial cells for adhesion of monocytes. In contrast, Aβ1–40 activation of endothelial cells for monocyte adhesion is reduced when more complete inhibition is observed. Conclusion These results demonstrate that inhibitors of Aβ self-assembly have the potential to trap small soluble aggregates resulting in an elevation rather than a reduction of cellular responses. These findings provide further support that small soluble aggregates possess high levels of physiological activity and underscore the importance of resolving the effect of Aβ aggregation inhibitors on aggregate size.
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Affiliation(s)
- Adriana A Reyes Barcelo
- Department of Chemical Engineering, University of South Carolina, 2C02 Swearingen Engineering Center, Columbia, South Carolina 29208, USA.
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137
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Kosenko EA, Solomadin IN, Marov NV, Venediktova NI, Pogosian AS, Kaminskiĭ IG. [Role of glycolysis and antioxidant enzymes in the toxicity of amyloid beta peptide Abeta25-35 to erythrocytes]. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2009; 34:654-60. [PMID: 19060940 DOI: 10.1134/s1068162008050087] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The role of glycolysis and antioxidant enzymes in amyloid beta peptide Abeta(25-35) toxicity to human and rat erythrocytes was studied. The erythrotoxicity of Abeta(25-35) was shown to increase two- to fourfold both in the absence of glucose in the incubation medium and upon the addition of sodium fluoride, an enolase inhibitor. Potassium cyanide, a Cu,Zn-superoxide dismutase inhibitor, abolishes the toxic effect of Abeta(25-35) to erythrocytes, whereas mercaptosuccinate, a glutathione peroxidase inhibitor, and ouabain, a Na+,K+-ATPase inhibitor, promote it. Sodium azide, a catalase inhibitor, did not affect the cell lysis under the action of Abeta(25-35) . The results support the hypothesis that H2O2, Cu,Zn superoxide dismutase, and glutathione peroxidase are involved in the toxicity mechanism rather than superoxide radical. Glycolysis and Na+,K+-ATPase play a substantial protective role. Fullerene C(60) nanoparticles are toxic to erythrocytes of both types; their toxicity is not related to enhanced oxidative stress and the mechanism of toxicity differs from that of Abeta(25-35) .
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138
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Roher AE, Esh CL, Kokjohn TA, Castaño EM, Van Vickle GD, Kalback WM, Patton RL, Luehrs DC, Daugs ID, Kuo YM, Emmerling MR, Soares H, Quinn JF, Kaye J, Connor DJ, Silverberg NB, Adler CH, Seward JD, Beach TG, Sabbagh MN. Amyloid beta peptides in human plasma and tissues and their significance for Alzheimer's disease. Alzheimers Dement 2009; 5:18-29. [PMID: 19118806 DOI: 10.1016/j.jalz.2008.10.004] [Citation(s) in RCA: 282] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2008] [Revised: 08/27/2008] [Accepted: 10/06/2008] [Indexed: 01/17/2023]
Abstract
BACKGROUND We evaluated the amounts of amyloid beta (Abeta)) peptides in the central nervous system (CNS) and in reservoirs outside the CNS and their potential impact on Abeta plasma levels and Alzheimer's disease (AD) pathology. METHODS Amyloid beta levels were measured in (1) the plasma of AD and nondemented (ND) controls in a longitudinal study, (2) the plasma of a cohort of AD patients receiving a cholinesterase inhibitor, and (3) the skeletal muscle, liver, aorta, platelets, leptomeningeal arteries, and in gray and white matter of AD and ND control subjects. RESULTS Plasma Abeta levels fluctuated over time and among individuals, suggesting continuous contributions from brain and peripheral tissues and associations with reactive circulating proteins. Arteries with atherosclerosis had larger amounts of Abeta40 than disease-free vessels. Inactivated platelets contained more Abeta peptides than activated ones. Substantially more Abeta was present in liver samples from ND patients. Overall, AD brain and skeletal muscle contained increased levels of Abeta. CONCLUSIONS Efforts to use plasma levels of Abeta peptides as AD biomarkers or disease-staging scales have failed. Peripheral tissues might contribute to both the circulating amyloid pool and AD pathology within the brain and its vasculature. The wide spread of plasma Abeta values is also due in part to the ability of Abeta to bind to a variety of plasma and membrane proteins. Sources outside the CNS must be accounted for because pharmacologic interventions to reduce cerebral amyloid are assessed by monitoring Abeta plasma levels. Furthermore, the long-range impact of Abeta immunotherapy on peripheral Abeta sources should also be considered.
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Affiliation(s)
- Alex E Roher
- The Longtine Center for Molecular Biology and Genetics, Sun Health Research Institute, Sun City, AZ, USA.
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139
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Monitoring the amyloid beta-peptide in vivo--caveat emptor. Drug Discov Today 2009; 14:241-51. [PMID: 19135168 DOI: 10.1016/j.drudis.2008.12.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2008] [Revised: 11/27/2008] [Accepted: 12/02/2008] [Indexed: 12/26/2022]
Abstract
As a wave of 'disease modifying' (DM) therapies for Alzheimer's disease (AD) progresses towards the later stages of clinical development, an evaluation of our ability to measure relevant pharmacodynamic effects of such therapies is warranted. Reducing accumulation of amyloid beta (Abeta)-peptide in the brain parenchyma is the primary objective of most current DM approaches. Although a number of methods are available to measure Abeta in blood, cerebrospinal fluid (CSF) and the cerebrum, putative DM-induced changes in the levels of the peptides may not be fully captured, and the reasons for any such changes are not fully understood. Additional candidate biofluid (tau and isoprostanes) and imaging (MRI, FDG-PET) measures may provide alternative supporting evidence of drug activity and subsequent clinical efficacy in patient populations.
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140
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Malaplate-Armand C, Desbene C, Pillot T, Olivier JL. [Biomarkers for early diagnosis of Alzheimer's disease: current update and future directions]. Rev Neurol (Paris) 2008; 165:511-20. [PMID: 19041993 DOI: 10.1016/j.neurol.2008.10.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2008] [Revised: 09/10/2008] [Accepted: 10/08/2008] [Indexed: 01/08/2023]
Abstract
INTRODUCTION The increased prevalence of the sporadic form of Alzheimer's disease (AD) has become a significant health issue in the elderly population. The need for early diagnosis is imperative because this, along with the development of novel therapeutic treatments, would permit the rapid and perhaps more efficient treatment of these debilitating disorders early on. BACKGROUND Over the last decade, the potential use of certain biomarkers in the cerebrospinal fluid (CSF), and more recently, in the plasma has been investigated. Among the candidates studied includes the neurotoxic amyloid beta peptide and the Tau protein. However, although these two proteins have been clearly shown to be directly related to the pathophysiology of this disorder, it has proven difficult to establish a clear relationship between plasma or CSF levels of Abeta and Tau and the incidence and severity of AD in patients. This is due in part to differences in methodologies related to the detection sensitivity, as well as the variations in the biological data and consequent interpretation of the biochemical and biological data. Peripheral cells, in particular platelets and skin fibroblasts, could be an alternative solution as peripheral biological markers for the early diagnosis of AD. These cells are easily accessible from patients. Furthermore, they would provide a means not only to validate potential therapeutic strategies, but also to study the mechanisms involved in the development of AD, including APP processing. PERSPECTIVES A combined strategy using both a fundamental mechanistic and an analytical approach of patient peripheral cells will allow the identification of new biological markers for AD, and hence permit immediate therapeutic strategies to be implemented.
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Affiliation(s)
- C Malaplate-Armand
- Laboratoire de biochimie spécialisée, hôpital Central, CHU de Nancy, CO 34, 54035 Nancy cedex, France.
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141
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Aluise CD, Sowell RA, Butterfield DA. Peptides and proteins in plasma and cerebrospinal fluid as biomarkers for the prediction, diagnosis, and monitoring of therapeutic efficacy of Alzheimer's disease. Biochim Biophys Acta Mol Basis Dis 2008; 1782:549-58. [PMID: 18760351 DOI: 10.1016/j.bbadis.2008.07.008] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2008] [Revised: 07/22/2008] [Accepted: 07/24/2008] [Indexed: 02/07/2023]
Abstract
Alzheimer's disease (AD) affects millions of persons worldwide. Earlier detection and/or diagnosis of AD would permit earlier intervention, which conceivably could delay progression of this dementing disorder. In order to accomplish this goal, reliable and specific biomarkers are needed. Biomarkers are multidimensional and have the potential to aid in various facets of AD such as diagnostic prediction, assessment of disease stage, discrimination from normally cognitive controls as well as other forms of dementia, and therapeutic efficacy of AD drugs. To date, biomarker research has focused on plasma and cerebrospinal fluid (CSF), two bodily fluids believed to contain the richest source of biomarkers for AD. CSF is the fluid surrounding the central nervous system (CNS), and is the most indicative obtainable fluid of brain pathology. Blood plasma contains proteins that affect brain processes from the periphery, as well as proteins/peptides exported from the brain; this fluid would be ideal for biomarker discovery due to the ease and non-invasive process of sample collection. However, it seems reasonable that biomarker discovery will result in combinations of CSF, plasma, and other fluids such as urine, to serve the aforementioned purposes. This review focuses on proteins and peptides identified from CSF, plasma, and urine that may serve as biomarkers in AD.
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Affiliation(s)
- Christopher D Aluise
- Department of Chemistry, Center of Membrane Sciences, and Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40506-0055, USA
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142
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Solomadin IN, Marov NV, Venediktova NI, Kosenko EA, Kaminsky YG. Toxic effect of Aβ25–35 and fullerene C60 on erythrocytes. BIOL BULL+ 2008. [DOI: 10.1134/s1062359008040171] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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143
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Maximizing the potential of plasma amyloid-beta as a diagnostic biomarker for Alzheimer's disease. Neuromolecular Med 2008; 10:195-207. [PMID: 18543125 DOI: 10.1007/s12017-008-8035-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2008] [Accepted: 05/06/2008] [Indexed: 12/15/2022]
Abstract
Amyloid plaques are composed primarily of amyloid-beta (Abeta) peptides derived from proteolytic cleavage of amyloid precursor protein (APP) and are considered to play a pivotal role in Alzheimer's disease (AD) pathogenesis. Presently, AD is diagnosed after the onset of clinical manifestations. With the arrival of novel therapeutic agents for treatment of AD, there is an urgent need for biomarkers to detect early stages of AD. Measurement of plasma Abeta has been suggested as an inexpensive and non-invasive tool to diagnose AD and to monitor Abeta modifying therapies. However, the majority of cross-sectional studies on plasma Abeta levels in humans have not shown differences between individuals with AD compared to controls. Similarly, cross-sectional studies of mouse plasma Abeta have yielded inconsistent trends in different mouse models. However, longitudinal studies appear to be more promising in humans. Recently, efforts to modify plasma Abeta levels using modulators have shown some promise. In this review, we will summarize the present data on plasma Abeta in humans and mouse models of AD. We will discuss the potential of modulators of Abeta levels in plasma, including antibodies and insulin, and the challenges associated with measuring plasma Abeta. Modulators of plasma Abeta may provide an important tool to optimize plasma Abeta levels and may improve the diagnostic potential of this approach.
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Beach TG, Sue LI, Walker DG, Roher AE, Lue L, Vedders L, Connor DJ, Sabbagh MN, Rogers J. The Sun Health Research Institute Brain Donation Program: description and experience, 1987-2007. Cell Tissue Bank 2008; 9:229-45. [PMID: 18347928 PMCID: PMC2493521 DOI: 10.1007/s10561-008-9067-2] [Citation(s) in RCA: 205] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2007] [Accepted: 11/08/2007] [Indexed: 11/30/2022]
Abstract
The Brain Donation Program at Sun Health Research Institute has been in continual operation since 1987, with over 1000 brains banked. The population studied primarily resides in the retirement communities of northwest metropolitan Phoenix, Arizona. The Institute is affiliated with Sun Health, a nonprofit community-owned and operated health care provider. Subjects are enrolled prospectively to allow standardized clinical assessments during life. Funding comes primarily from competitive grants. The Program has made short postmortem brain retrieval a priority, with a 2.75-h median postmortem interval for the entire collection. This maximizes the utility of the resource for molecular studies; frozen tissue from approximately 82% of all cases is suitable for RNA studies. Studies performed in-house have shown that, even with very short postmortem intervals, increasing delays in brain retrieval adversely affect RNA integrity and that cerebrospinal fluid pH increases with postmortem interval but does not predict tissue viability.
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145
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Lichtlen P, Mohajeri MH. Antibody-based approaches in Alzheimer’s research: safety, pharmacokinetics, metabolism, and analytical tools. J Neurochem 2008; 104:859-74. [DOI: 10.1111/j.1471-4159.2007.05064.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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146
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Rózga M, Kłoniecki M, Jabłonowska A, Dadlez M, Bal W. The binding constant for amyloid Aβ40 peptide interaction with human serum albumin. Biochem Biophys Res Commun 2007; 364:714-8. [DOI: 10.1016/j.bbrc.2007.10.080] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2007] [Accepted: 10/16/2007] [Indexed: 10/22/2022]
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147
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Lanz TA, Schachter JB. Solid-phase extraction enhances detection of beta-amyloid peptides in plasma and enables Abeta quantification following passive immunization with Abeta antibodies. J Neurosci Methods 2007; 169:16-22. [PMID: 18160105 DOI: 10.1016/j.jneumeth.2007.11.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2007] [Revised: 11/16/2007] [Accepted: 11/17/2007] [Indexed: 12/01/2022]
Abstract
We have previously developed a solid-phase extraction (SPE) procedure to enable the detection of beta-amyloid (Abeta) peptides in brain tissue from non-transgenic animals. We have now adapted these methods to enrich the Abeta fraction in cerebrospinal fluid (CSF) and plasma. Human CSF and plasma and Tg2576 mouse plasma were subjected to guanidine denaturation followed by SPE in 96-well cassettes. The resulting eluates could be concentrated significantly to enhance detection of low-abundance Abeta peptides by immunoassay. The concentrated eluates diluted in a linear fashion with consistent recovery between SPE columns. This technique was therefore used to facilitate quantification of Abeta1-X, 1-40, 1-42, and 1-38 peptides in normal human CSF and plasma samples. SPE sample preparation was also applied to the plasma of mice dosed peripherally with a monoclonal antibody raised against Abeta. When such samples were assayed directly, the presence of the systemically administered antibody interfered with the subsequent immunoassay, by preventing detection of antibody-bound Abeta. After subjecting plasma from antibody-treated animals to denaturation and SPE, the antibody-antigen complex was disrupted, and the Abeta fraction could be isolated from the antibody-containing fraction. Application of this method allowed for detection of a 100-fold increase in plasma Abeta1-40 following treatment of Tg2576 mice or wild type littermate control mice with Abeta40-specific monoclonal antibody 9TL. Given the availability of a variety of SPE matrices, we hypothesize that these methods could facilitate plasma antigen retrieval using multiple therapeutic antibody approaches.
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Affiliation(s)
- Thomas A Lanz
- CNS Biology, Pfizer Inc., Groton, CT 06340, United States.
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Beach TG, Sue LI, Walker DG, Roher AE, Lue L, Vedders L, Connor DJ, Sabbagh MN, Rogers J. The Sun Health Research Institute Brain Donation Program: description and experience, 1987–2007. Cell Tissue Bank 2007. [DOI: 10.1007/s10561-007-9056-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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149
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Uberti D, Cenini G, Olivari L, Ferrari-Toninelli G, Porrello E, Cecchi C, Pensalfini A, Pensafini A, Liguri G, Govoni S, Racchi M, Maurizio M. Over-expression of amyloid precursor protein in HEK cells alters p53 conformational state and protects against doxorubicin. J Neurochem 2007; 103:322-33. [PMID: 17608641 DOI: 10.1111/j.1471-4159.2007.04757.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Here we show that human embryonic kidney (HEK) cells stably transfected with amyloid precursor protein (HEK-APP), expressed a conformational mutant-like and transcriptionally inactive p53 isoform, and turned out to be less sensitive to the cytotoxin doxorubicin in comparison with untransfected cells. Treatment of HEK-APP cells with gamma- and beta-secretase inhibitors prevented generation of unfolded, mutant-like p53 isoform and made the cells vulnerable to doxorubicin as untransfected cells. Changes in p53 conformational state and reduced sensitivity to doxorubicin were also found in untransfected HEK cells after exposure to nanomolar concentrations of beta-amyloid (Abeta) and these effects were antagonized by vitamin E. The modulator effects of Abeta on p53 conformational state were, at least in part, due to the intracellular peptides as (i) treatment of HEK-APP cells with an antibody that sequestered extracellular Abeta did not modify the capability of the cells to express the mutant-like p53 isoform; (ii) in the presence of 1% serum exogenous Abeta peptide crossed the plasma membrane, as demonstrated by confocal analysis and ELISA, and induced p53 conformational change; and (iii) in the presence of 10% serum Abeta did not enter the cells and consequently did not influence the p53 conformational state.
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Affiliation(s)
- Daniela Uberti
- Department of Biomedical Sciences and Biotechnologies, University of Brescia, Brescia, Italy.
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Abstract
Currently, there are no disease-modifying therapies available for Alzheimer's disease (AD). Acetylcholinesterase inhibitors and memantine are licensed for AD and have moderate symptomatic benefits. Epidemiological studies have suggested that NSAIDs, estrogen, HMG-CoA reductase inhibitors (statins) or tocopherol (vitamin E) can prevent AD. However, prospective, randomised studies have not convincingly been able to demonstrate clinical efficacy. Major progress in molecular medicine suggests further drug targets. The metabolism of the amyloid-precursor protein and the aggregation of its Abeta fragment are the focus of current studies. Abeta peptides are produced by the enzymes beta- and gamma-secretase. Inhibition of gamma-secretase has been shown to reduce Abeta production. However, gamma-secretase activity is also involved in other vital physiological pathways. Involvement of gamma-secretase in cell differentiation may preclude complete blockade of gamma-secretase for prolonged times in vivo. Inhibition of beta-secretase seems to be devoid of serious adverse effects according to studies with knockout animals. However, targeting beta-secretase is hampered by the lack of suitable inhibitors to date. Other approaches focus on enzymes that cut inside the Abeta sequence such as alpha-secretase and neprilysin. Stimulation of the expression or activity of alpha-secretase or neprilysin has been shown to enhance Abeta degradation. Furthermore, inhibitors of Abeta aggregation have been described and clinical trials have been initiated. Peroxisome proliferator activated receptor-gamma agonists and selected NSAIDs may be suitable to modulate both Abeta production and inflammatory activation. On the basis of autopsy reports, active immunisation against Abeta in humans seems to have proven its ability to clear amyloid deposits from the brain. However, a first clinical trial with active vaccination against the full length Abeta peptide has been halted because of adverse effects. Further trials with vaccination or passive transfer of antibodies are planned.
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Affiliation(s)
- Michael Hüll
- Department of Psychiatry and Psychotherapy, University of Freiburg, Hauptstrasse 5, D-79108 Freiburg, Germany.
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