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Castellani RJ, Moreira PI, Liu G, Dobson J, Perry G, Smith MA, Zhu X. Iron: the Redox-active center of oxidative stress in Alzheimer disease. Neurochem Res 2007; 32:1640-5. [PMID: 17508283 DOI: 10.1007/s11064-007-9360-7] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2007] [Accepted: 04/17/2007] [Indexed: 01/24/2023]
Abstract
Although iron is essential in maintaining the function of the central nervous system, it is a potent source of reactive oxygen species. Excessive iron accumulation occurs in many neurodegenerative diseases including Alzheimer disease (AD), Parkinson's disease, and Creutzfeldt-Jakob disease, raising the possibility that oxidative stress is intimately involved in the neurodegenerative process. AD in particular is associated with accumulation of numerous markers of oxidative stress; moreover, oxidative stress has been shown to precede hallmark neuropathological lesions early in the disease process, and such lesions, once present, further accumulate iron, among other markers of oxidative stress. In this review, we discuss the role of iron in the progression of AD.
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102
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Falangola MF, Dyakin VV, Lee SP, Bogart A, Babb JS, Duff K, Nixon R, Helpern JA. Quantitative MRI reveals aging-associated T2 changes in mouse models of Alzheimer's disease. NMR IN BIOMEDICINE 2007; 20:343-51. [PMID: 17451178 DOI: 10.1002/nbm.1163] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
In this study, we used MRI to analyze quantitative parametric maps of transverse (T(2)) relaxation times in a longitudinal study of transgenic mice expressing mutant forms of amyloid precursor protein (APP), presenilin (PS1), or both (PS/APP), modeling aspects of Alzheimer's disease (AD). The main goal was to characterize the effects of progressive beta-amyloid accumulation and deposition on the biophysical environment of water and to investigate if these measurements would provide early indirect evidence of AD pathological changes in the brains of these mice. Our results demonstrate that at an early age before beta-amyloid deposition, only PS/APP mice show a reduced T(2) in the hippocampus and cortex compared with wild-type non-transgenic (NTg) controls, whereas a statistically significant within-group aging-associated decrease in T(2) values is seen in the cortex and hippocampus of all three transgenic genotypes (APP, PS/APP, and PS) but not in the NTg controls. In addition, for animals older than 12 months, we confirmed our previous report that only the two genotypes that form amyloid plaques (APP and PS/APP) have significantly reduced T(2) values compared with NTg controls. Thus, T(2) changes in these AD models can precede amyloid deposition or even occur in AD models that do not deposit beta-amyloid (PS mice), but are intensified in the presence of amyloid deposition.
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Affiliation(s)
- M F Falangola
- Center for Advanced Brain Imaging, Nathan Kline Institute for Psychiatric Research, 140 Old Orangeburg Road, Orangeburg, NY 10962, USA.
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103
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Beckmann N, Kneuer R, Gremlich HU, Karmouty-Quintana H, Blé FX, Müller M. In vivo mouse imaging and spectroscopy in drug discovery. NMR IN BIOMEDICINE 2007; 20:154-85. [PMID: 17451175 DOI: 10.1002/nbm.1153] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Imaging modalities such as micro-computed tomography (micro-CT), micro-positron emission tomography (micro-PET), high-resolution MRI, optical imaging, and high-resolution ultrasound have become invaluable tools in preclinical pharmaceutical research. They can be used to non-invasively investigate, in vivo, rodent biology and metabolism, disease models, and pharmacokinetics and pharmacodynamics of drugs. The advantages and limitations of each approach usually determine its application, and therefore a small-rodent imaging laboratory in a pharmaceutical environment should ideally provide access to several techniques. In this paper we aim to illustrate how these techniques may be used to obtain meaningful information for the phenotyping of transgenic mice and for the analysis of compounds in murine models of disease.
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Affiliation(s)
- Nicolau Beckmann
- Discovery Technologies, Novartis Institutes for BioMedical Research, Lichtstrasse 35, CH-4002 Basel, Switzerland.
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104
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Choi JK, Dedeoglu A, Jenkins BG. Application of MRS to mouse models of neurodegenerative illness. NMR IN BIOMEDICINE 2007; 20:216-37. [PMID: 17451183 DOI: 10.1002/nbm.1145] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The rapid development of transgenic mouse models of neurodegenerative diseases, in parallel with the rapidly expanding growth of MR techniques for assessing in vivo, non-invasive, neurochemistry, offers the potential to develop novel markers of disease progression and therapy. In this review we discuss the interpretation and utility of MRS for the study of these transgenic mouse and rodent models of neurodegenerative diseases such as Alzheimer's (AD), Huntington's (HD) and Parkinson's disease (PD). MRS studies can provide a wealth of information on various facets of in vivo neurochemistry, including neuronal health, gliosis, osmoregulation, energy metabolism, neuronal-glial cycling, and molecular synthesis rates. These data provide information on the etiology, natural history and therapy of these diseases. Mouse models enable longitudinal studies with useful time frames for evaluation of neuroprotection and therapeutic interventions using many of the potential MRS markers. In addition, the ability to manipulate the genome in these models allows better mechanistic understanding of the roles of the observable neurochemicals, such as N-acetylaspartate, in the brain. The argument is made that use of MRS, combined with correlative histology and other MRI techniques, will enable objective markers with which potential therapies can be followed in a quantitative fashion.
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Affiliation(s)
- Ji-Kyung Choi
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
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105
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Abstract
MRI has contributed to significant advances in the understanding of neurological diseases in humans. It has also been used to evaluate the spectrum of mouse models spanning from developmental abnormalities during embryogenesis, evaluation of transgenic and knockout models, through various neurological diseases such as stroke, tumors, degenerative and inflammatory diseases. The MRI techniques used clinically are technically more challenging in the mouse because of the size of the brain; however, mouse imaging provides researchers with the ability to explore cellular and molecular imaging that one day may translate into clinical practice. This article presents an overview of the use of MRI in mouse models of a variety of neurological disorders and a brief review of cellular imaging using magnetically tagged cells in the mouse central nervous system.
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Affiliation(s)
- Stasia A Anderson
- Animal MRI/Imaging Core, National Heart Lung and Blood Institute, National Institutes of Health, 10 Center Drive, Bethesda, MD 20892, USA.
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106
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Benveniste H, Ma Y, Dhawan J, Gifford A, Smith SD, Feinstein I, Du C, Grant SC, Hof PR. Anatomical and functional phenotyping of mice models of Alzheimer's disease by MR microscopy. Ann N Y Acad Sci 2007; 1097:12-29. [PMID: 17413006 DOI: 10.1196/annals.1379.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The wide variety of transgenic mouse models of Alzheimer's disease (AD) reflects the search for specific genes that influence AD pathology and the drive to create a clinically relevant animal model. An ideal AD mouse model must display hallmark AD pathology such as amyloid plaques, neurofibrillary tangles, reactive gliosis, dystrophic neurites, neuron and synapse loss, and brain atrophy and in parallel behaviorally mimic the cognitive decline observed in humans. Magnetic resonance (MR) microscopy (MRM) can detect amyloid plaque load, development of brain atrophy, and acute neurodegeneration. MRM examples of AD pathology will be presented and discussed. What has lagged behind in preclinical research using transgenic AD mouse models is functional phenotyping of the brain; in other words, the ability to correlate a specific genotype with potential aberrant brain activation patterns. This lack of information is caused by the technical challenges involved in performing functional MRI (fMRI) in mice including the effects of anesthetic agents and the lack of relevant "cognitive" paradigms. An alternative approach to classical fMRI using external stimuli as triggers of brain activation in rodents is to electrically or pharmacologically stimulate regions directly while simultaneously locally tracking the activated interconnected regions of rodents using, for example, the manganese-enhanced MRI (MEMRI) technique. Finally, transgenic mouse models, MRM, and future AD research would be strengthened by the ability to screen for AD-like pathology in other non-AD transgenic mouse models. For example, molecular biologists may focus on cardiac or pulmonary pathologies in transgenic mice models and as an incidental finding discover behavioral AD phenotypes. We will present MRM data of brain and cardiac phenotyping in transgenic mouse models with behavioral deficits.
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Affiliation(s)
- Helene Benveniste
- Brookhaven National Laboratory, Medical Department, Bldg. 490, 30 Bell Avenue, Upton, NY 11973, USA.
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107
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Poduslo JF, Ramakrishnan M, Holasek SS, Ramirez-Alvarado M, Kandimalla KK, Gilles EJ, Curran GL, Wengenack TM. In vivo targeting of antibody fragments to the nervous system for Alzheimer’s disease immunotherapy and molecular imaging of amyloid plaques. J Neurochem 2007; 102:420-33. [PMID: 17596213 DOI: 10.1111/j.1471-4159.2007.04591.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Targeting therapeutic or diagnostic proteins to the nervous system is limited by the presence of the blood-brain barrier. We report that a F(ab')(2) fragment of a monoclonal antibody against fibrillar human Abeta42 that is polyamine (p)-modified has increased permeability at the blood-brain barrier, comparable binding to the antigen, and comparable in vitro binding to amyloid plaques in Alzheimer's disease (AD) transgenic mouse brain sections. Intravenous injection of the pF(ab')(2)4.1 in the AD transgenic mouse demonstrated efficient targeting to amyloid plaques throughout the brain, whereas the unmodified fragment did not. Removal of the Fc portion of this antibody derivative will minimize the inflammatory response and cerebral hemorrhaging associated with passive immunization and provide increased therapeutic potential for treating AD. Coupling contrast agents/radioisotopes might facilitate the molecular imaging of amyloid plaques with magnetic resonance imaging/positron emission tomography. The efficient delivery of immunoglobulin G fragments may also have important applications to other neurodegenerative disorders or for the generalized targeting of nervous system antigens.
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MESH Headings
- Alzheimer Disease/immunology
- Alzheimer Disease/physiopathology
- Alzheimer Disease/therapy
- Amyloid beta-Peptides/antagonists & inhibitors
- Amyloid beta-Peptides/immunology
- Animals
- Antibodies, Monoclonal/immunology
- Antibodies, Monoclonal/metabolism
- Antibodies, Monoclonal/therapeutic use
- Binding, Competitive/immunology
- Blood-Brain Barrier/drug effects
- Blood-Brain Barrier/immunology
- Cell Line, Tumor
- Electrophoresis, Polyacrylamide Gel
- Humans
- Immunoglobulin Fragments/immunology
- Immunoglobulin Fragments/metabolism
- Immunoglobulin Fragments/therapeutic use
- Immunoglobulin G/immunology
- Immunoglobulin G/metabolism
- Immunoglobulin G/therapeutic use
- Immunotherapy/methods
- Immunotherapy/trends
- Injections, Intravenous
- Isoelectric Focusing
- Mice
- Mice, Transgenic
- Peptide Fragments/antagonists & inhibitors
- Peptide Fragments/immunology
- Peptide Hydrolases/chemistry
- Plaque, Amyloid/drug effects
- Plaque, Amyloid/immunology
- Protein Binding/immunology
- Protein Transport/immunology
- Radioligand Assay
- Receptors, Immunologic/drug effects
- Receptors, Immunologic/metabolism
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Affiliation(s)
- Joseph F Poduslo
- Molecular Neurobiology Laboratory, Department of Neurology, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA.
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108
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Jack CR, Marjanska M, Wengenack TM, Reyes DA, Curran GL, Lin J, Preboske GM, Poduslo JF, Garwood M. Magnetic resonance imaging of Alzheimer's pathology in the brains of living transgenic mice: a new tool in Alzheimer's disease research. Neuroscientist 2007; 13:38-48. [PMID: 17229974 DOI: 10.1177/1073858406295610] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Alzheimer's disease (AD) is the most common cause of dementia in the elderly. Cardinal pathologic features of AD are amyloid plaques and neurofibrillary tangles, and most in the field believe that the initiating events ultimately leading to clinical AD center on disordered metabolism of amyloid beta protein. Mouse models of AD have been created by inserting one or more human mutations associated with disordered amyloid metabolism and that cause early onset familial AD into the mouse genome. Human-like amyloid plaque formation increases dramatically with age in these transgenic mice. Amyloid reduction in humans is a major therapeutic objective, and AD transgenic mice allow controlled study of this biology. Recent work has shown that amyloid plaques as small as 35 microm can be detected using in vivo magnetic resonance microimaging (MRMI) at high magnetic field (9.4 T). In addition, age-dependent changes in metabolite concentration analogous to those that have been identified in human AD patients can be detected in these transgenic mice using single-voxel (1)H magnetic resonance spectroscopy ((1)H MRS) at high magnetic field. These MR-based techniques provide a new set of tools to the scientific community engaged in studying the biology of AD in transgenic models of the disease. For example, an obvious application is evaluating therapeutic modification of disease progression. Toward the end of this review, the authors include results from a pilot study demonstrating feasibility of using MRMI to detect therapeutic modification of plaque progression in AD transgenic mice.
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Affiliation(s)
- Clifford R Jack
- Mayo Clinic, Department of Radiology, 200 First Street SW, Rochester, MN 55905, USA.
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109
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Strome EM, Doudet DJ. Animal Models of Neurodegenerative Disease: Insights from In vivo Imaging Studies. Mol Imaging Biol 2007; 9:186-95. [PMID: 17357857 DOI: 10.1007/s11307-007-0093-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Animal models have been used extensively to understand the etiology and pathophysiology of human neurodegenerative diseases, and are an essential component in the development of therapeutic interventions for these disorders. In recent years, technical advances in imaging modalities such as positron emission tomography (PET) and magnetic resonance imaging (MRI) have allowed the use of these techniques for the evaluation of functional, neurochemical, and anatomical changes in the brains of animals. Combining animal models of neurodegenerative disorders with neuroimaging provides a powerful tool to follow the disease process, to examine compensatory mechanisms, and to investigate the effects of potential treatments preclinically to derive knowledge that will ultimately inform our clinical decisions. This article reviews the literature on the use of PET and MRI in animal models of Parkinson's disease, Huntington's disease, and Alzheimer's disease, and evaluates the strengths and limitations of brain imaging in animal models of neurodegenerative diseases.
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Affiliation(s)
- Elissa M Strome
- Pacific Parkinson's Research Centre, University of British Columbia, Vancouver, Canada.
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110
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House MJ, St Pierre TG, Kowdley KV, Montine T, Connor J, Beard J, Berger J, Siddaiah N, Shankland E, Jin LW. Correlation of proton transverse relaxation rates (R2) with iron concentrations in postmortem brain tissue from alzheimer's disease patients. Magn Reson Med 2007; 57:172-80. [PMID: 17191232 DOI: 10.1002/mrm.21118] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Iron accumulates in the Alzheimer's disease (AD) brain and is directly associated with beta-amyloid pathology. The proton transverse relaxation rate (R(2)) has a strong linear relationship with iron concentrations in healthy brain tissue; however, an independent test of this relationship has not been extended to AD brain tissue. In this study in vitro single spin-echo (SE) measurements were made on tissue samples from four human AD brains using a 4.7T MRI research scanner. R(2) values were calculated for 14 cortical and subcortical gray matter (GM) and white matter (WM) regions. Atomic absorption spectroscopy was used to measure iron concentrations in the corresponding excised brain regions. Significant positive linear correlations were observed between R(2) values and iron concentrations in GM regions assessed across individual tissue samples and data averaged by brain region. With the use of a predictive model for R(2), a threshold iron concentration of 55 microg Fe/g wet tissue was determined above which R(2) appears to be dominated by the affects of iron in AD brain tissue. High-field MRI may therefore be a useful research tool for assessing brain iron changes associated with AD.
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Affiliation(s)
- Michael J House
- School of Physics, University of Western Australia, Perth, Australia.
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111
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Sigurdsson EM, Wadghiri YZ, Mosconi L, Blind JA, Knudsen E, Asuni A, Scholtzova H, Tsui WH, Li Y, Sadowski M, Turnbull DH, de Leon MJ, Wisniewski T. A non-toxic ligand for voxel-based MRI analysis of plaques in AD transgenic mice. Neurobiol Aging 2007; 29:836-47. [PMID: 17291630 PMCID: PMC2408732 DOI: 10.1016/j.neurobiolaging.2006.12.018] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2006] [Revised: 12/22/2006] [Accepted: 12/31/2006] [Indexed: 01/08/2023]
Abstract
Amyloid plaques are a characteristic feature in Alzheimer's disease (AD). A novel non-toxic contrast agent is presented, Gd-DTPA-K6Abeta1-30, which is homologous to Abeta, and allows plaque detection in vivo. microMRI was performed on AD model mice and controls prior to and following intracarotid injection with Gd-DTPA-K6Abeta1-30 in mannitol solution, to transiently open the blood-brain barrier. A gradient echo T2(*)-weighted sequence was used to provide 100 microm isotropic resolution with imaging times of 115 min. The scans were examined with voxel-based analysis (VBA) using statistical parametric mapping, for un-biased quantitative comparison of ligand-injected mice and controls. The results indicate that: (1) Gd-DTPA-K6Abeta1-30 is an effective, non-toxic, ligand for plaque detection when combined with VBA (p< or =0.01-0.001), comparing pre and post-ligand injection scans. (2) Large plaques can be detected without the use of a contrast agent and this detection co-localizes with iron deposition. (3) Smaller, earlier plaques require contrast ligand for MRI visualization. Our ligand when combined with VBA may be useful for following therapeutic approaches targeting amyloid in transgenic mouse models.
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Affiliation(s)
- Einar M. Sigurdsson
- Department of Psychiatry; New York University School of Medicine, New York, NY
- Department of Pathology; New York University School of Medicine, New York, NY
| | - Youssef Z. Wadghiri
- Department of Radiology; New York University School of Medicine, New York, NY
| | - Lisa Mosconi
- Department of Psychiatry; New York University School of Medicine, New York, NY
| | - Jeffrey A. Blind
- Skirball Institute for Biomolecular Medicine; New York University School of Medicine, New York, NY
| | - Elin Knudsen
- Department of Psychiatry; New York University School of Medicine, New York, NY
| | - Ayodeji Asuni
- Department of Psychiatry; New York University School of Medicine, New York, NY
| | - Henrieta Scholtzova
- Department of Neurology; New York University School of Medicine, New York, NY
| | - Wai H. Tsui
- Department of Psychiatry; New York University School of Medicine, New York, NY
| | - Yongsheng Li
- Department of Neurology; New York University School of Medicine, New York, NY
| | - Martin Sadowski
- Department of Neurology; New York University School of Medicine, New York, NY
| | - Daniel H. Turnbull
- Department of Radiology; New York University School of Medicine, New York, NY
- Department of Neurology; New York University School of Medicine, New York, NY
- Skirball Institute for Biomolecular Medicine; New York University School of Medicine, New York, NY
| | - Mony J. de Leon
- Department of Psychiatry; New York University School of Medicine, New York, NY
- Nathan Kline Institute Orangeburg NY. USA
| | - Thomas Wisniewski
- Department of Psychiatry; New York University School of Medicine, New York, NY
- Department of Pathology; New York University School of Medicine, New York, NY
- Department of Neurology; New York University School of Medicine, New York, NY
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112
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Moffett JR, Ross B, Arun P, Madhavarao CN, Namboodiri AMA. N-Acetylaspartate in the CNS: from neurodiagnostics to neurobiology. Prog Neurobiol 2007; 81:89-131. [PMID: 17275978 PMCID: PMC1919520 DOI: 10.1016/j.pneurobio.2006.12.003] [Citation(s) in RCA: 991] [Impact Index Per Article: 58.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2006] [Revised: 12/07/2006] [Accepted: 12/11/2006] [Indexed: 01/02/2023]
Abstract
The brain is unique among organs in many respects, including its mechanisms of lipid synthesis and energy production. The nervous system-specific metabolite N-acetylaspartate (NAA), which is synthesized from aspartate and acetyl-coenzyme A in neurons, appears to be a key link in these distinct biochemical features of CNS metabolism. During early postnatal central nervous system (CNS) development, the expression of lipogenic enzymes in oligodendrocytes, including the NAA-degrading enzyme aspartoacylase (ASPA), is increased along with increased NAA production in neurons. NAA is transported from neurons to the cytoplasm of oligodendrocytes, where ASPA cleaves the acetate moiety for use in fatty acid and steroid synthesis. The fatty acids and steroids produced then go on to be used as building blocks for myelin lipid synthesis. Mutations in the gene for ASPA result in the fatal leukodystrophy Canavan disease, for which there is currently no effective treatment. Once postnatal myelination is completed, NAA may continue to be involved in myelin lipid turnover in adults, but it also appears to adopt other roles, including a bioenergetic role in neuronal mitochondria. NAA and ATP metabolism appear to be linked indirectly, whereby acetylation of aspartate may facilitate its removal from neuronal mitochondria, thus favoring conversion of glutamate to alpha ketoglutarate which can enter the tricarboxylic acid cycle for energy production. In its role as a mechanism for enhancing mitochondrial energy production from glutamate, NAA is in a key position to act as a magnetic resonance spectroscopy marker for neuronal health, viability and number. Evidence suggests that NAA is a direct precursor for the enzymatic synthesis of the neuron specific dipeptide N-acetylaspartylglutamate, the most concentrated neuropeptide in the human brain. Other proposed roles for NAA include neuronal osmoregulation and axon-glial signaling. We propose that NAA may also be involved in brain nitrogen balance. Further research will be required to more fully understand the biochemical functions served by NAA in CNS development and activity, and additional functions are likely to be discovered.
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Affiliation(s)
- John R Moffett
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Building C, 4301 Jones Bridge Rd., Bethesda, MD 20814, USA.
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113
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Lehéricy S, Marjanska M, Mesrob L, Sarazin M, Kinkingnehun S. Magnetic resonance imaging of Alzheimer's disease. Eur Radiol 2006; 17:347-62. [PMID: 16865367 DOI: 10.1007/s00330-006-0341-z] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2006] [Revised: 05/12/2006] [Accepted: 05/22/2006] [Indexed: 10/24/2022]
Abstract
A modern challenge for neuroimaging techniques is to contribute to the early diagnosis of neurodegenerative diseases, such as Alzheimer's disease (AD). Early diagnosis includes recognition of pre-demented conditions, such as mild cognitive impairment (MCI) or having a high risk of developing AD. The role of neuroimaging therefore extends beyond its traditional role of excluding other conditions such as neurosurgical lesions. In addition, early diagnosis would allow early treatment using currently available therapies or new therapies in the future. Structural imaging can detect and follow the time course of subtle brain atrophy as a surrogate marker for pathological processes. New MR techniques and image analysis software can detect subtle brain microstructural, perfusion or metabolic changes that provide new tools to study the pathological processes and detect pre-demented conditions. This review focuses on markers of macro- and microstructural, perfusion, diffusion and metabolic MR imaging and spectroscopy in AD.
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Affiliation(s)
- Stéphane Lehéricy
- Department of Neuroradiology, Université Pierre et Marie Curie-Paris 6, Groupe Hospitalier Pitié-Salpêtrière, 47-83 boulevard de l'Hôpital, Paris 75651, Cedex 13, France.
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114
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Abstract
In vivo microscopy is an exciting tool for neurological research because it can reveal how single cells respond to damage of the nervous system. This helps us to understand how diseases unfold and how therapies work. Here, we review the optical imaging techniques used to visualize the different parts of the nervous system, and how they have provided fresh insights into the aetiology and therapeutics of neurological diseases. We focus our discussion on five areas of neuropathology (trauma, degeneration, ischaemia, inflammation and seizures) in which in vivo microscopy has had the greatest impact. We discuss the challenging issues in the field, and argue that the convergence of new optical and non-optical methods will be necessary to overcome these challenges.
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Affiliation(s)
- Thomas Misgeld
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, USA.
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