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Lopez FV, O'Shea A, Huo Z, DeKosky ST, Trouard TP, Alexander GE, Woods AJ, Bowers D. Frontal-temporal regional differences in brain energy metabolism and mitochondrial function using 31P MRS in older adults. GeroScience 2024; 46:3185-3195. [PMID: 38225480 PMCID: PMC11009166 DOI: 10.1007/s11357-023-01046-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 12/07/2023] [Indexed: 01/17/2024] Open
Abstract
Aging is a major risk for cognitive decline and transition to dementia. One well-known age-related change involves decreased brain efficiency and energy production, mediated in part by changes in mitochondrial function. Damaged or dysfunctional mitochondria have been implicated in the pathogenesis of age-related neurodegenerative conditions like Alzheimer's disease (AD). The aim of the current study was to investigate mitochondrial function over frontal and temporal regions in a sample of 70 cognitively normal older adults with subjective memory complaints and a first-degree family history of AD. We hypothesized cerebral mitochondrial function and energy metabolism would be greater in temporal as compared to frontal regions based on the high energy consumption in the temporal lobes (i.e., hippocampus). To test this hypothesis, we used phosphorous (31P) magnetic resonance spectroscopy (MRS) which is a non-invasive and powerful method for investigating in vivo mitochondrial function via high energy phosphates and phospholipid metabolism ratios. We used a single voxel method (left temporal and bilateral prefrontal) to achieve optimal sensitivity. Results of separate repeated measures analyses of variance showed 31P MRS ratios of static energy, energy reserve, energy consumption, energy demand, and phospholipid membrane metabolism were greater in the left temporal than bilateral prefrontal voxels. Our findings that all 31P MRS ratios were greater in temporal than bifrontal regions support our hypothesis. Future studies are needed to determine whether findings are related to cognition in older adults.
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Affiliation(s)
- Francesca V Lopez
- Department of Clinical and Health Psychology, College of Public Health and Health Professions, University of Florida, PO Box 100165, Gainesville, FL, 32610, USA.
| | - Andrew O'Shea
- Center for Cognitive Aging and Memory, Evelyn F. McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | - Zhiguang Huo
- Department of Biostatistics, College of Public Health and Health Professions and College of Medicine, University of Florida, Gainesville, FL, USA
| | - Steven T DeKosky
- Department of Neurology, Fixel Center for Neurological Diseases, College of Medicine, and Evelyn F. McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | - Theodore P Trouard
- Department of Biomedical Engineering, College of Engineering, and Evelyn F. McKnight Brain Institute, University of Arizona and Alzheimer's Disease Consortium, Tucson, AZ, USA
| | - Gene E Alexander
- Department of Psychology and Evelyn F. McKnight Brain Institute, University of Arizona, Tucson, AZ, USA
- Department of Psychiatry, Neuroscience and Physiological Sciences Graduate Interdisciplinary Programs, and BIO5 Institute, University of Arizona and Arizona Alzheimer's Disease Consortium, Tucson, AZ, USA
| | - Adam J Woods
- Department of Clinical and Health Psychology, College of Public Health and Health Professions, University of Florida, PO Box 100165, Gainesville, FL, 32610, USA
- Center for Cognitive Aging and Memory, Evelyn F. McKnight Brain Institute, University of Florida, Gainesville, FL, USA
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Dawn Bowers
- Department of Clinical and Health Psychology, College of Public Health and Health Professions, University of Florida, PO Box 100165, Gainesville, FL, 32610, USA
- Department of Neurology, Fixel Center of Neurological Diseases, College of Medicine, University of Florida, Gainesville, FL, USA
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Jett S, Boneu C, Zarate C, Carlton C, Kodancha V, Nerattini M, Battista M, Pahlajani S, Williams S, Dyke JP, Mosconi L. Systematic review of 31P-magnetic resonance spectroscopy studies of brain high energy phosphates and membrane phospholipids in aging and Alzheimer's disease. Front Aging Neurosci 2023; 15:1183228. [PMID: 37273652 PMCID: PMC10232902 DOI: 10.3389/fnagi.2023.1183228] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 05/02/2023] [Indexed: 06/06/2023] Open
Abstract
Many lines of evidence suggest that mitochondria have a central role in aging-related neurodegenerative diseases, such as Alzheimer's disease (AD). Mitochondrial dysfunction, cerebral energy dysmetabolism and oxidative damage increase with age, and are early event in AD pathophysiology and may precede amyloid beta (Aβ) plaques. In vivo probes of mitochondrial function and energy metabolism are therefore crucial to characterize the bioenergetic abnormalities underlying AD risk, and their relationship to pathophysiology and cognition. A majority of the research conducted in humans have used 18F-fluoro-deoxygluose (FDG) PET to image cerebral glucose metabolism (CMRglc), but key information regarding oxidative phosphorylation (OXPHOS), the process which generates 90% of the energy for the brain, cannot be assessed with this method. Thus, there is a crucial need for imaging tools to measure mitochondrial processes and OXPHOS in vivo in the human brain. 31Phosphorus-magnetic resonance spectroscopy (31P-MRS) is a non-invasive method which allows for the measurement of OXPHOS-related high-energy phosphates (HEP), including phosphocreatine (PCr), adenosine triphosphate (ATP), and inorganic phosphate (Pi), in addition to potential of hydrogen (pH), as well as components of phospholipid metabolism, such as phosphomonoesters (PMEs) and phosphodiesters (PDEs). Herein, we provide a systematic review of the existing literature utilizing the 31P-MRS methodology during the normal aging process and in patients with mild cognitive impairment (MCI) and AD, with an additional focus on individuals at risk for AD. We discuss the strengths and limitations of the technique, in addition to considering future directions toward validating the use of 31P-MRS measures as biomarkers for the early detection of AD.
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Affiliation(s)
- Steven Jett
- Department of Neurology, Weill Cornell Medical College, New York, NY, United States
| | - Camila Boneu
- Department of Neurology, Weill Cornell Medical College, New York, NY, United States
| | - Camila Zarate
- Department of Neurology, Weill Cornell Medical College, New York, NY, United States
| | - Caroline Carlton
- Department of Neurology, Weill Cornell Medical College, New York, NY, United States
| | - Vibha Kodancha
- Department of Neurology, Weill Cornell Medical College, New York, NY, United States
| | - Matilde Nerattini
- Department of Neurology, Weill Cornell Medical College, New York, NY, United States
- Nuclear Medicine Unit, Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy
| | - Michael Battista
- Department of Neurology, Weill Cornell Medical College, New York, NY, United States
| | - Silky Pahlajani
- Department of Neurology, Weill Cornell Medical College, New York, NY, United States
- Department of Radiology, Weill Cornell Medical College, New York, NY, United States
| | - Schantel Williams
- Department of Neurology, Weill Cornell Medical College, New York, NY, United States
| | - Jonathan P. Dyke
- Department of Radiology, Weill Cornell Medical College, New York, NY, United States
| | - Lisa Mosconi
- Department of Neurology, Weill Cornell Medical College, New York, NY, United States
- Department of Radiology, Weill Cornell Medical College, New York, NY, United States
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Mitochondrial dysfunction, oxidative stress, neuroinflammation, and metabolic alterations in the progression of Alzheimer's disease: A meta-analysis of in vivo magnetic resonance spectroscopy studies. Ageing Res Rev 2021; 72:101503. [PMID: 34751136 DOI: 10.1016/j.arr.2021.101503] [Citation(s) in RCA: 86] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 10/19/2021] [Accepted: 10/25/2021] [Indexed: 12/13/2022]
Abstract
Accumulating evidence demonstrates that metabolic changes in the brain associated with neuroinflammation, oxidative stress, and mitochondrial dysfunction play an important role in the pathophysiology of mild cognitive impairment (MCI) and Alzheimer's disease (AD). However, the neural signatures associated with these metabolic alterations and underlying molecular mechanisms are still elusive. Accordingly, we reviewed the literature on in vivo human brain 1H and 31P-MRS studies and use meta-analyses to identify patterns of brain metabolic alterations in MCI and AD. 40 and 39 studies on MCI and AD, respectively, were classified according to brain regions. Our results indicate decreased N-acetyl aspartate and creatine but increased myo-inositol levels in both MCI and AD, decreased glutathione level in MCI as well as disrupted energy metabolism in AD. In addition, the hippocampus shows the strongest alterations in most of these metabolites. This meta-analysis also illustrates progressive metabolite alterations from MCI to AD. Taken together, it suggests that 1) neuroinflammation and oxidative stress may occur in the early stages of AD, and likely precede neuron loss in its progression; 2) the hippocampus is a sensitive region of interest for early diagnosis and monitoring the response of interventions; 3) targeting bioenergetics associated with neuroinflammation/oxidative stress is a promising approach for treating AD.
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Das N, Ren J, Spence JS, Rackley A, Chapman SB. Relationship of Parieto-Occipital Brain Energy Phosphate Metabolism and Cognition Using 31P MRS at 7-Tesla in Amnestic Mild Cognitive Impairment. Front Aging Neurosci 2020; 12:222. [PMID: 33005142 PMCID: PMC7483543 DOI: 10.3389/fnagi.2020.00222] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 06/22/2020] [Indexed: 01/02/2023] Open
Abstract
Background The human brain has high energy requirements that continuously support healthy neuronal activity and cognition. A disruption in brain energy metabolism (BEM) may contribute to early neuropathological changes such as accumulation of β-amyloid and tau in vulnerable populations. One such population is amnestic mild cognitive impairment (aMCI) where some individuals are at risk for developing dementia, i.e. Alzheimer’s disease (AD). Recent advances in imaging technology are providing new avenues to measure BEM accurately using 31phosphorus magnetic resonance spectroscopy (31P MRS) at ultra-high-field (UHF) magnetic strength 7-Tesla. This study investigates whether a methodology using partial volume-coil 31P MRS at 7T over parieto-occipital lobes can accurately quantify high-energy phosphate and membrane phospholipid metabolites in aMCI. A secondary objective was to explore BEM and membrane phospholipid indices’ correspondence with cognitive performance in domains of executive function (EF), memory, attention, and visuospatial skills in aMCI, a heterogeneous population. Methods 19 aMCI participants enrolled in the study completed cognitive assessment and 31P MRS scan. BEM indices were measured using three energy indicators: energy reserve (PCr/t-ATP), energy consumption (intracellular_Pi/t-ATP), and metabolic state (PCr/intracellular_Pi) along with regulatory co-factors of BEM-intracellular Mg2 + and pH; whereas the ratio of phosphomonoesters (PMEs) to phosphodiesters (PDEs) – membrane phospholipid indicator. Results 31P MRS scan showed thirteen well-resolved peaks with precise quantification of the phosphorus metabolites at UHF. The higher BEM indices were associated with lower cognitive performance of memory [(energy reserve indicator: CVLT p = 0.004), (metabolic state indicator: CVLT p = 0.007)], executive function [(metabolic state indicator: TOSL (p = 0.044)], and attention [(pH: selective auditory task, p = 0.044)]. The finding of an inverse relationship observed in the parieto-occipital lobes suggests an association between neuronal energy markers with cognition in aMCI. Conclusion The significant contribution of this preliminary research was to establish the feasibility of utilizing a methodology at UHF to accurately measure high-energy phosphate and membrane phospholipid metabolites in a population with heterogeneous outcomes. This work offers a novel approach for future work to further elucidate early dementia biomarkers or precursors to the downstream accumulation of amyloid and tau using the combination of MRS-PET imaging modalities in AD.
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Affiliation(s)
- Namrata Das
- Center for BrainHealth, The University of Texas at Dallas, Dallas, TX, United States
| | - Jimin Ren
- Advanced Imaging Research Center, and Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Jeffrey S Spence
- Center for BrainHealth, The University of Texas at Dallas, Dallas, TX, United States
| | - Audette Rackley
- Center for BrainHealth, The University of Texas at Dallas, Dallas, TX, United States
| | - Sandra B Chapman
- Center for BrainHealth, The University of Texas at Dallas, Dallas, TX, United States
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Mecheri G, Marie-Cardine M, Sappey-Marinier D, Bonmartin H, Albrand G, Ferry G, Coppard-Meyer N, Courpron P. In vivo hippocampal 31P NMR metabolites in Alzheimer's disease and ageing. Eur Psychiatry 2020; 12:140-8. [DOI: 10.1016/s0924-9338(97)80203-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/1996] [Accepted: 03/11/1997] [Indexed: 11/16/2022] Open
Abstract
SummaryMemory loss is the most common early symptom of Alzheimer's disease (AD). For this study, we chose the hippocampi as regions of interest. The hippocampus, which is closely associated with memory processing, is known to be vulnerable to damage in the early stage of AD. We considered both inter-group (patients vs controls) and intra-group (right vs left hippocampus) comparisons. We examined seven patients meeting the DSM-III-R criteria of senile dementia and the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association (NINCDS — ADRDA) criteria of probable AD, and II aged controls. This study focused on the measurement of phosphorus 31 (31P) Nuclear Magnetic Resonance (NMR) spectroscopy metabolites in each hippocampus. We found significant differences in phosphorus metabolites for both intra-group comparison (pH shifted towards relative alkalosis in the left hippocampus of patients) and inter-group consideration (reduced phosphodiesters [Pde]and elevated gamma adenosine triphosphate (ATP) in the right hippocampus, higher inorganic phosphate (pHi) in the left hippocampus for patients as compared to controls). We suggest energy failure and membrane functional breakdown in patients compared to aged controls.
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Kim MS, Lee S, Yun S, Suh PG, Park J, Cui M, Choi S, Cha SS, Jin W. Inhibitory effect of tartrate against phosphate-induced DJ-1 aggregation. Int J Biol Macromol 2018; 107:1650-1658. [DOI: 10.1016/j.ijbiomac.2017.10.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 09/30/2017] [Accepted: 10/05/2017] [Indexed: 12/19/2022]
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Zhang A, Mu Y, Wu F. An enantiomer-based virtual screening approach: Discovery of chiral organophosphates as acetyl cholinesterase inhibitors. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2017; 138:215-222. [PMID: 28061415 DOI: 10.1016/j.ecoenv.2016.12.035] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 12/23/2016] [Accepted: 12/27/2016] [Indexed: 06/06/2023]
Abstract
Chiral organophosphates (OPs) have been used widely around the world, very little is known about binding mechanisms with biological macromolecules. An in-depth understanding of the stereo selectivity of human AChE and discovering bioactive enantiomers of OPs can decrease health risks of these chiral chemicals. In the present study, a flexible molecular docking approach was conducted to investigate different binding modes of twelve phosphorus enantiomers. A pharmacophore model was then developed on basis of the bioactive conformations of these compounds. After virtual screening, twenty-four potential bioactive compounds were found, of which three compounds (Ethyl p-nitrophenyl phenylphosphonate (EPN), 1-naphthaleneacetic anhydride and N,4-dimethyl-N-phenyl-benzenesulfonamide) were tested by use of different in vitro assays. S-isomer of EPN was also found to exhibit greater inhibitory activity towards human AChE than the corresponding R-isomer. These findings affirm that stereochemistry plays a crucial role in virtual screening, and provide a new insight into designing safer organ phosphorus pesticides on human health.
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Affiliation(s)
- Aiqian Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yunsong Mu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
| | - Fengchang Wu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
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8
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Montagna P, Pierangeli G, Cortelli P, Zaniol P, Funicello R, Lugaresi E, Barbiroli B. Brain Oxidative Metabolism in Parkinson's Disease Studied by Phosphorus 31 Magnetic Resonance Spectroscopy. J Neuroimaging 2016. [DOI: 10.1111/jon199334225] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Brown R, Lakshmanan K, Madelin G, Parasoglou P. A nested phosphorus and proton coil array for brain magnetic resonance imaging and spectroscopy. Neuroimage 2016; 124:602-611. [PMID: 26375209 PMCID: PMC4651763 DOI: 10.1016/j.neuroimage.2015.08.066] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 08/04/2015] [Accepted: 08/28/2015] [Indexed: 02/02/2023] Open
Abstract
A dual-nuclei radiofrequency coil array was constructed for phosphorus and proton magnetic resonance imaging and spectroscopy of the human brain at 7T. An eight-channel transceive degenerate birdcage phosphorus module was implemented to provide whole-brain coverage and significant sensitivity improvement over a standard dual-tuned loop coil. A nested eight-channel proton module provided adequate sensitivity for anatomical localization without substantially sacrificing performance on the phosphorus module. The developed array enabled phosphorus spectroscopy, a saturation transfer technique to calculate the global creatine kinase forward reaction rate, and single-metabolite whole-brain imaging with 1.4cm nominal isotropic resolution in 15min (2.3cm actual resolution), while additionally enabling 1mm isotropic proton imaging. This study demonstrates that a multi-channel array can be utilized for phosphorus and proton applications with improved coverage and/or sensitivity over traditional single-channel coils. The efficient multi-channel coil array, time-efficient pulse sequences, and the enhanced signal strength available at ultra-high fields can be combined to allow volumetric assessment of the brain and could provide new insights into the underlying energy metabolism impairment in several neurodegenerative conditions, such as Alzheimer's and Parkinson's diseases, as well as mental disorders such as schizophrenia.
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Affiliation(s)
- Ryan Brown
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA; Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, USA; NYU WIRELESS, Polytechnic Institute of New York University, 2 Metro Tech Center, Brooklyn, NY 11201, USA.
| | - Karthik Lakshmanan
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA; Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, USA
| | - Guillaume Madelin
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA; Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, USA
| | - Prodromos Parasoglou
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA; Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, USA
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Lu M, Chen W, Zhu XH. Field dependence study of in vivo brain (31) P MRS up to 16.4 T. NMR IN BIOMEDICINE 2014; 27:1135-41. [PMID: 25070004 PMCID: PMC4180101 DOI: 10.1002/nbm.3167] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2014] [Revised: 06/16/2014] [Accepted: 06/17/2014] [Indexed: 05/05/2023]
Abstract
In vivo (31) P MRS provides a unique tool for studying bioenergetics of living organs. Although its utility has been limited by the relatively low (31) P NMR sensitivity, increasing magnetic field strength (B0 ) could significantly improve the quality and reliability of the (31) P MR spectra for biomedical research. To quantitatively understand the field dependence of in vivo (31) P MRS for brain applications, (31) P NMR sensitivity of phosphocreatine (PCr) in rat brains was measured and compared at 9.4 T and 16.4 T. Additionally, the linewidths and T1 relaxation times of PCr and adenosine triphosphate (ATP) resonances obtained from human and animal brains over a wide B0 range from 4 T, 7 T, and 9.4 T to 16.4 T were examined and their field dependences were quantified. The results indicate an approximate 1.74-fold (31) P signal-to-noise ratio (SNR) gain for PCr at 16.4 T compared with 9.4 T. An approximate power 1.4 dependence of (31) P SNR on B0 was concluded. Substantial improvements in spectral resolution and significantly shortened T1 values of brain PCr and ATP were observed at high/ultrahigh fields, contributing to an additional sensitivity gain and spectral improvement. In summary, the overall findings from this study suggest that in vivo (31) P MRS should greatly benefit from high/ultrahigh fields for noninvasive assessment of altered bioenergetics and metabolic processes associated with brain function and neurological diseases.
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Affiliation(s)
- Ming Lu
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA
| | - Wei Chen
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA
| | - Xiao-Hong Zhu
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA
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Abstract
Neurodegenerative dementias are characterized by elevated myoinositol and decreased N-acetylaspartate (NAA) levels. The increase in myoinositol seems to precede decreasing NAA levels in Alzheimer's diseases. NAA/myo-inositol ratio in the posterior cingulate gyri decreases with increasing burden of Alzheimer's disease pathologic conditions. Proton magnetic resonance spectroscopy ((1)H MRS) is sensitive to the pathophysiologic processes associated with the risk of dementia in patients with mild cognitive impairment. Although significant progress has been made in improving the acquisition and analysis techniques in (1)H MRS, translation of these technical developments to clinical practice have not been effective because of the lack of standardization for multisite applications and normative data and an insufficient understanding of the pathologic basis of (1)H MRS metabolite changes.
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Lu A, Atkinson IC, Zhou XJ, Thulborn KR. PCr/ATP ratio mapping of the human head by simultaneously imaging of multiple spectral peaks with interleaved excitations and flexible twisted projection imaging readout trajectories at 9.4 T. Magn Reson Med 2013; 69:538-44. [PMID: 22529019 PMCID: PMC4552734 DOI: 10.1002/mrm.24281] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Revised: 02/27/2012] [Accepted: 03/13/2012] [Indexed: 11/08/2022]
Abstract
Quantitative (31)P magnetic resonance imaging of the whole human brain is often time-consuming even at low spatial resolution due to the low concentrations, long T(1) relaxation times, and low detection sensitivity of phosphorus metabolites. We report herein the results of combining the increased detection sensitivity of an ultra-high field 9.4 T scanner designed for human imaging with a new pulse sequence termed simultaneously imaging of multiple spectral peaks with interleaved excitations and flexible twisted projection imaging readout trajectories to rapidly sample multiple resonances in the (31)P spectrum. The phosphocreatine and γ-adenosine triphosphate images, obtained simultaneously from the entire human head, are demonstrated at 1.5 cm isotropic nominal resolution in a total acquisition time of 33 min. The phosphocreatine/γ-adenosine triphosphate ratio calculated for brain parenchyma (1-2) and the superficial temporalis muscle (3-5) are in agreement with literature values.
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Affiliation(s)
- Aiming Lu
- Center for Magnetic Resonance Research, University of Illinois at Chicago, Chicago, Illinois 60612, USA.
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13
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Role of Cytosolic Calcium-Dependent Phospholipase A2 in Alzheimer's Disease Pathogenesis. Mol Neurobiol 2012; 45:596-604. [DOI: 10.1007/s12035-012-8279-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Accepted: 05/08/2012] [Indexed: 12/13/2022]
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Schaeffer EL, Skaf HD, Novaes BDA, da Silva ER, Martins BA, Joaquim HDG, Gattaz WF. Inhibition of phospholipase A₂ in rat brain modifies different membrane fluidity parameters in opposite ways. Prog Neuropsychopharmacol Biol Psychiatry 2011; 35:1612-7. [PMID: 21601609 DOI: 10.1016/j.pnpbp.2011.05.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Revised: 05/06/2011] [Accepted: 05/06/2011] [Indexed: 11/29/2022]
Abstract
Fluidity is an important neuronal membrane property and it is influenced by the concentration of polyunsaturated fatty acids (PUFAs) in membrane phospholipids. Phospholipase A(2) (PLA(2)) is a key enzyme in membrane phospholipid metabolism, generating free PUFAs. In Alzheimer disease (AD), reduced PLA(2) activity, specifically of calcium-dependent cytosolic PLA(2) (cPLA(2)) and calcium-independent intracellular PLA(2) (iPLA(2)), and phospholipid metabolism was reported in the frontal cortex and hippocampus. This study investigated the effects of in vivo infusion of the dual cPLA(2) and iPLA(2) inhibitor MAFP into rat brain on PLA(2) activity and membrane fluidity parameters in the postmortem frontal cortex and dorsal hippocampus. PLA(2) activity was measured by radioenzymatic assay and membrane fluidity was determined by fluorescence anisotropy technique using three different probes: DPH, TMA-DPH, and pyrene. MAFP significantly inhibited PLA(2) activity, reduced the flexibility of fatty acyl chains (indicated by increased DPH anisotropy), increased the fluidity in the lipid-water interface (indicated by decreased TMA-DPH anisotropy), and increased the lipid lateral diffusion in the hydrocarbon core (represented by pyrene excimer formation) of membranes in both brain areas. The findings suggest that reduced cPLA(2) and iPLA(2) activities in AD brain might contribute to the cognitive impairment, in part, through alterations in membrane fluidity parameters.
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Affiliation(s)
- Evelin L Schaeffer
- Laboratory of Neuroscience (LIM-27), Department and Institute of Psychiatry, Faculty of Medicine, University of São Paulo, Rua Doutor Ovídio Pires de Campos 785, 05403-010, São Paulo, SP, Brazil.
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15
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Schaeffer EL, da Silva ER, Novaes BDA, Skaf HD, Gattaz WF. Differential roles of phospholipases A2 in neuronal death and neurogenesis: implications for Alzheimer disease. Prog Neuropsychopharmacol Biol Psychiatry 2010; 34:1381-9. [PMID: 20804810 DOI: 10.1016/j.pnpbp.2010.08.019] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2010] [Revised: 08/04/2010] [Accepted: 08/21/2010] [Indexed: 01/06/2023]
Abstract
The involvement of phospholipase A(2) (PLA(2)) in Alzheimer disease (AD) was first investigated nearly 15 years ago. Over the years, several PLA(2) isoforms have been detected in brain tissue: calcium-dependent secreted PLA(2) or sPLA(2) (IIA, IIC, IIE, V, X, and XII), calcium-dependent cytosolic PLA(2) or cPLA(2) (IVA, IVB, and IVC), and calcium-independent PLA(2) or iPLA(2) (VIA and VIB). Additionally, numerous in vivo and in vitro studies have suggested the role of different brain PLA(2) in both physiological and pathological events. This review aimed to summarize the findings in the literature relating the different brain PLA(2) isoforms with alterations found in AD, such as neuronal cell death and impaired neurogenesis process. The review showed that sPLA(2)-IIA, sPLA(2)-V and cPLA(2)-IVA are involved in neuronal death, whereas sPLA(2)-III and sPLA(2)-X are related to the process of neurogenesis, and that the cPLA(2) and iPLA(2) groups can be involved in both neuronal death and neurogenesis. In AD, there are reports of reduced activity of the cPLA(2) and iPLA(2) groups and increased expression of sPLA(2)-IIA and cPLA(2)-IVA. The findings suggest that the inhibition of cPLA(2) and iPLA(2) isoforms (yet to be determined) might contribute to impaired neurogenesis, whereas stimulation of sPLA(2)-IIA and cPLA(2)-IVA might contribute to neurodegeneration in AD.
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Affiliation(s)
- Evelin L Schaeffer
- Laboratory of Neuroscience (LIM-27), Department and Institute of Psychiatry, Faculty of Medicine, University of Sao Paulo, Rua Dr. Ovídio Pires de Campos 785, 05403-010, Sao Paulo, SP, Brazil.
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Amtul Z, Uhrig M, Supino R, Beyreuther K. Phospholipids and a phospholipid-rich diet alter the in vitro amyloid-beta peptide levels and amyloid-beta 42/40 ratios. Neurosci Lett 2010; 481:73-7. [PMID: 20600609 DOI: 10.1016/j.neulet.2010.06.046] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2010] [Revised: 05/25/2010] [Accepted: 06/15/2010] [Indexed: 10/19/2022]
Abstract
Amyloid-beta peptides (Abeta) generated by proteolysis of the beta-amyloid precursor protein (APP) by beta- and gamma-secretases play an important role in the pathogenesis of Alzheimer's disease (AD). There is mounting evidence that the lipid matrix of neuronal cell membranes plays an important role in the accumulation of Abeta peptides into senile plaques, one of the hallmarks of AD. With the aim to clarify the molecular basis of the interaction between Abeta and cellular membranes, we investigated the effects of various phospholipids (PLs) and a PL-rich diet on Abeta production. Here we show that modulation of Abeta production and Abeta42:40 ratio is not limited to individual fatty acids, rather it is the composition of the PLs of the membrane bilayer, that influences the specificity and level of the regulated intramembranous proteolysis of APP by the gamma-secretase complex. We show that Abeta levels in the conditioned media, in response to some of the PL supplements, is increased in the center and decreased on either side of a graph that resembles bell-shaped distribution. This means that the PLs have less of a tendency to produce unusually extreme effects on Abeta production in SP-C99 transfected Cos-7 cultured cells. We proposed a mechanism-based hypothesis to rationalize PLs' effects on Abeta production.
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Affiliation(s)
- Zareen Amtul
- Zentrum für Molekulare Biologie Heidelberg, University of Heidelberg, Germany.
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17
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Cordeiro Q, Noguti R, Bottino CM, Vallada H. Study of association between genetic polymorphisms of phospholipase A2 enzymes and Alzheimer's disease. ARQUIVOS DE NEURO-PSIQUIATRIA 2010; 68:189-93. [DOI: 10.1590/s0004-282x2010000200007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2009] [Accepted: 10/05/2009] [Indexed: 11/21/2022]
Abstract
Several genes have been related to late-onset Alzheimer's disease (LOAD). Phospholipases A2 (PLA2) influence the processing and secretion of the amyloid precursor protein, which gives rise to the beta-amyloid peptide, the major component of the amyloid plaque in AD. Hence, in the present study, polymorphisms of three genes encoding PLA2 enzymes group (cytosolic PLA2: BanI cPLA2 polymorphism; calcium-independent PLA2: AvrII iPLA2 polymorphism; PAFAH: Val279Phe PAFAH polymorphism) were analysed in a case-control sample using 58 patients with LOAD and 107 matched healthy controls. There was a genotypic association between the BanI cPLA2 polymorphism and LOAD (χ2=6.25, 2df, p=0.04), however there was no allelic association. There were no associations between AvrII iPLA2 and Val279Phe PAFAH polymorphisms and LOAD. These data suggest that the BanI cPLA2 polymorphism may play a role in the susceptibility for LOAD in our Brazilian sample.
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Schaeffer EL, Forlenza OV, Gattaz WF. Phospholipase A2 activation as a therapeutic approach for cognitive enhancement in early-stage Alzheimer disease. Psychopharmacology (Berl) 2009; 202:37-51. [PMID: 18853146 DOI: 10.1007/s00213-008-1351-0] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2008] [Accepted: 09/10/2008] [Indexed: 11/29/2022]
Abstract
RATIONALE Alzheimer disease (AD) is the leading cause of dementia in the elderly and has no known cure. Evidence suggests that reduced activity of specific subtypes of intracellular phospholipases A2 (cPLA2 and iPLA2) is an early event in AD and may contribute to memory impairment and neuropathology in the disease. OBJECTIVE The objective of this study was to review the literature focusing on the therapeutic role of PLA2 stimulation by cognitive training and positive modulators, or of supplementation with arachidonic acid (PLA2 product) in facilitating memory function and synaptic transmission and plasticity in either research animals or human subjects. METHODS MEDLINE database was searched (no date restrictions) for published articles using the keywords Alzheimer disease (mild, moderate, severe), mild cognitive impairment, healthy elderly, rats, mice, phospholipase A(2), phospholipid metabolism, phosphatidylcholine, arachidonic acid, cognitive training, learning, memory, long-term potentiation, protein kinases, dietary lipid compounds, cell proliferation, neurogenesis, and neuritogenesis. Reference lists of the identified articles were checked to select additional studies of interest. RESULTS Overall, the data suggest that PLA2 activation is induced in the healthy brain during learning and memory. Furthermore, learning seems to regulate endogenous neurogenesis, which has been observed in AD brains. Finally, PLA2 appears to be implicated in homeostatic processes related to neurite outgrowth and differentiation in both neurodevelopmental processes and response to neuronal injury. CONCLUSION The use of positive modulators of PLA2 (especially of cPLA2 and iPLA2) or supplementation with dietary lipid compounds (e.g., arachidonic acid) in combination with cognitive training could be a valuable therapeutic strategy for cognitive enhancement in early-stage AD.
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Affiliation(s)
- Evelin L Schaeffer
- Laboratory of Neuroscience (LIM-27), Department and Institute of Psychiatry, Faculty of Medicine, University of São Paulo, Rua Dr. Ovídio Pires de Campos 785, 05403-010 São Paulo, SP, Brazil.
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Zhu XH, Du F, Zhang N, Zhang Y, Lei H, Zhang X, Qiao H, Ugurbil K, Chen W. Advanced In Vivo Heteronuclear MRS Approaches for Studying Brain Bioenergetics Driven by Mitochondria. Methods Mol Biol 2009; 489:317-57. [PMID: 18839099 PMCID: PMC5348251 DOI: 10.1007/978-1-59745-543-5_15] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The greatest merit of in vivo magnetic resonance spectroscopy (MRS) methodology used in biomedical research is its ability for noninvasively measuring a variety of metabolites inside a living organ. It, therefore, provides an invaluable tool for determining metabolites, chemical reaction rates and bioenergetics, as well as their dynamic changes in the human and animal. The capability of in vivo MRS is further enhanced at higher magnetic fields because of significant gain in detection sensitivity and improvement in the spectral resolution. Recent progress of in vivo MRS technology has further demonstrated its great potential in many biomedical research areas, particularly in brain research. Here, we provide a review of new developments for in vivo heteronuclear 31P and 17O MRS approaches and their applications in determining the cerebral metabolic rates of oxygen and ATP inside the mitochondria, in both animal and human brains.
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Affiliation(s)
- Xiao-Hong Zhu
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, School of Medicine, Minneapolis, MN, USA
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20
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Cha SS, Jung HI, Jeon H, An YJ, Kim IK, Yun S, Ahn HJ, Chung KC, Lee SH, Suh PG, Kang SO. Crystal structure of filamentous aggregates of human DJ-1 formed in an inorganic phosphate-dependent manner. J Biol Chem 2008; 283:34069-75. [PMID: 18922803 DOI: 10.1074/jbc.m804243200] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Mutations in the DJ-1 gene have been implicated in the autosomal recessive early onset parkinsonism. DJ-1 is a soluble dimeric protein with critical roles in response to oxidative stress and in neuronal maintenance. However, several lines of evidence suggest the existence of a nonfunctional aggregated form of DJ-1 in the brain of patients with some neurodegenerative diseases. Here, we show that inorganic phosphate, an important anion that exhibits elevated levels in patients with Parkinson disease, transforms DJ-1 into filamentous aggregates. According to the 2.4-A crystal structure, DJ-1 dimers are linearly stacked through P(i)-mediated interactions to form protofilaments, which are then bundled into a filamentous assembly.
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Affiliation(s)
- Sun-Shin Cha
- Marine and Extreme Genome Research Center, Korea Ocean Research & Development Institute, Ansan 426-744, Republic of Korea.
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21
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Cholinergic and glutamatergic alterations beginning at the early stages of Alzheimer disease: participation of the phospholipase A2 enzyme. Psychopharmacology (Berl) 2008; 198:1-27. [PMID: 18392810 DOI: 10.1007/s00213-008-1092-0] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2007] [Accepted: 01/28/2008] [Indexed: 12/14/2022]
Abstract
RATIONALE Alzheimer disease (AD), a progressive neurodegenerative disorder, is the leading cause of dementia in the elderly. A combination of cholinergic and glutamatergic dysfunction appears to underlie the symptomatology of AD, and thus, treatment strategies should address impairments in both systems. Evidence suggests the involvement of phospholipase A(2) (PLA(2)) enzyme in memory impairment and neurodegeneration in AD via actions on both cholinergic and glutamatergic systems. OBJECTIVES To review cholinergic and glutamatergic alterations underlying cognitive impairment and neuropathology in AD and attempt to link PLA(2) with such alterations. METHODS Medline databases were searched (no date restrictions) for published articles with links among the terms Alzheimer disease (mild, moderate, severe), mild cognitive impairment, choline acetyltransferase, acetylcholinesterase, NGF, NGF receptor, muscarinic receptor, nicotinic receptor, NMDA, AMPA, metabotropic glutamate receptor, atrophy, glucose metabolism, phospholipid metabolism, sphingolipid, membrane fluidity, phospholipase A(2), arachidonic acid, attention, memory, long-term potentiation, beta-amyloid, tau, inflammation, and reactive species. Reference lists of the identified articles were checked to identify additional studies of interest. RESULTS Overall, results suggest the hypothesis that persistent inhibition of cPLA(2) and iPLA(2) isoforms at early stages of AD may play a central role in memory deficits and beta-amyloid production through down-regulation of cholinergic and glutamate receptors. As the disease progresses, beta-amyloid induced up-regulation of cPLA(2) and sPLA(2) isoforms may play critical roles in inflammation and oxidative stress, thus participating in the neurodegenerative process. CONCLUSION Activation and inhibition of specific PLA(2) isoforms at different stages of AD could be of therapeutic importance and delay cognitive dysfunction and neurodegeneration.
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Buratta M, Piccotti L, Giannini S, Gresele P, Roberti R, Corazzi L. Selective Cytochrome c Displacement by Phosphate and Ca2+ in Brain Mitochondria. J Membr Biol 2007; 212:199-210. [PMID: 17334837 DOI: 10.1007/s00232-006-0015-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2006] [Revised: 06/11/2006] [Indexed: 10/23/2022]
Abstract
In brain mitochondria, phosphate- and Ca(2+)-dependent cytocrome c (cyt c) release reveals pools that interact differently with the inner membrane. Detachment of the phosphate-dependent pool did not influence the pool released by Ca(2+). Cyt c pools were also detected in a system of cyt c reconstituted in cardiolipin (CL) liposomes. Gradual binding of cyt c (1 nmol) to CL/2-[12-(7-nitrobenz- 2-oxa-1,3-diazol-4-yl)amino]dodecanoyl-1-hexadecan oyl-sn-glycero-3-phosphocholine (NBDC(12)-HPC) liposomes (10 nmol) produced NBD fluorescence quenching up to 0.4 nmol of added protein. Additional bound cyt c did not produce quenching, suggesting that cyt c-CL interactions originate distinct cyt c pools. Cyt c was removed from CL/NBDC(12)-HPC liposomes by either phosphate or Ca(2+), but only Ca(2+) produced fluorescence dequenching and leakage of encapsulated 8-aminonaphthalene-1,3,6-trisulfonic acid/p-xylene-bis-pyridinium bromide. In mitochondria, complex IV activity and mitochondrial membrane potential (Deltapsi(m)) were not affected by the release of the phosphate-dependent cyt c pool. Conversely, removal of cyt c by Ca(2+) caused inhibition of complex IV activity and impairment of Deltapsi(m). In a reconstituted system of mitochondria, nuclei and supernatant, cyt c detached from the inner membrane was released outside mitochondria and triggered events leading to DNA fragmentation. These events were prevented by enriching mitochondria with exogenous CL or by sequestering released cyt c with anti-cyt c antibody.
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Affiliation(s)
- Morena Buratta
- Laboratory of Biochemistry, Department of Internal Medicine, University of Perugia, Via del Giochetto, 06122, Perugia, Italy
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23
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Moreira PI, Santos MS, Seiça R, Oliveira CR. Brain mitochondrial dysfunction as a link between Alzheimer's disease and diabetes. J Neurol Sci 2007; 257:206-14. [PMID: 17316694 DOI: 10.1016/j.jns.2007.01.017] [Citation(s) in RCA: 130] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
It has been argued that in late-onset Alzheimer's disease a disturbance in the control of neuronal glucose metabolism consequent to impaired insulin signalling strongly resembles the pathophysiology of type 2 diabetes in non-neural tissue. The fact that mitochondria are the major generators and direct targets of reactive oxygen species led several investigators to foster the idea that oxidative stress and damage in mitochondria are contributory factors to several disorders including Alzheimer's disease and diabetes. Since brain possesses high energetic requirements, any decline in brain mitochondria electron chain could have a severe impact on brain function and particularly on the etiology of neurodegenerative diseases. This review is primarily focused in the discussion of brain mitochondrial dysfunction as a link between diabetes and Alzheimer's disease.
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Affiliation(s)
- Paula I Moreira
- Center for Neuroscience and Cell Biology, Institute of Physiology, Faculty of Medicine, University of Coimbra, 3004-354 Coimbra, Portugal
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Long-term abnormalities in brain glucose/energy metabolism after inhibition of the neuronal insulin receptor: implication of tau-protein. JOURNAL OF NEURAL TRANSMISSION. SUPPLEMENTUM 2007:195-202. [PMID: 17982895 DOI: 10.1007/978-3-211-73574-9_25] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The triplicate intracerebroventricular (icv) application of the diabetogenic compound streptozotocin (STZ) in low dosage was used in 1-year-old male Wistar rats to induce a damage of the neuronal insulin signal transduction (IST) system and to investigate the activities of hexokinase (HK), phosphofructokinase (PFK), glyceraldehyde-3-phosphate dehydrogenase (GDH), pyruvate kinase (PK), lactate dehydrogenase (LDH) and alpha-ketoglutarate dehydrogenase (alpha-KGDH) in frontoparietotemporal brain cortex (ct) and hippocampus (h) 9 weeks after damage. In parallel, the concentrations of adenosine triphosphate (ATP), adenosine diphosphate (ADP), guanosine triphosphate (GTP) and creatine phosphate (CrP) were determined. We found reductions of HK to 53% (ct) and 60% (h) of control, PFK to 63/64% (ct/h); GDH to 56/61% (ct/h), PFK to 57/59% (ct/h), alpha-KGDH to 37/35% (ct/h) and an increase of LDH to 300/240% (ct/h). ATP decreased to 82/87% (ct/h) of control, GTP to 69/81% (ct/h), CrP to 82/81% (ct/h), approximately P to 82/82% (ct/h), whereas ADP increased to 189/154% (ct/h). The fall of the activities of the glycolytic enzymes HK, PFK, GDH and PK was found to be more marked after 9 weeks of damage when compared with 3- and 6-week damage whereas the diminution in the concentration of energy rich compound was stably reduced by between 20 and 10% relative to control. The abnormalities in glucose/energy metabolism were discussed in relation to tau-protein mismetabolism of experimental animals, and of sporadic AD.
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Qiao H, Zhang X, Zhu XH, Du F, Chen W. In vivo 31P MRS of human brain at high/ultrahigh fields: a quantitative comparison of NMR detection sensitivity and spectral resolution between 4 T and 7 T. Magn Reson Imaging 2006; 24:1281-6. [PMID: 17145398 PMCID: PMC2610491 DOI: 10.1016/j.mri.2006.08.002] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2006] [Accepted: 08/24/2006] [Indexed: 11/19/2022]
Abstract
The primary goal of this study was to establish a rigorous approach for determining and comparing the NMR detection sensitivity of in vivo 31P MRS at different field strengths (B0). This was done by calculating the signal-to-noise ratio (SNR) achieved within a unit sampling time at a given field strength. In vivo 31P spectra of human occipital lobe were acquired at 4 and 7 T under similar experimental conditions. They were used to measure the improvement of the human brain 31P MRS when the field strength increases from 4 to 7 T. The relaxation times and line widths of the phosphocreatine (PCr) resonance peak and the RF coil quality factors (Q) were also measured at these two field strengths. Their relative contributions to SNR at a given field strength were analyzed and discussed. The results show that in vivo 31P sensitivity was significantly improved at 7 T as compared with 4 T. Moreover, the line-width of the PCr resonance peak showed less than a linear increase with increased B0, which leads to a significant improvement in 31P spectral resolution. These findings indicate the advantage of high-field strength to improve in vivo 31P MRS quality in both sensitivity and spectral resolution. This advantage should improve the reliability and applicability of in vivo 31P MRS in studying high-energy phosphate metabolism, phospholipid metabolism and cerebral biogenetics in the human at both normal and diseased states noninvasively. Finally, the approach used in this study for calculating in vivo 31P MRS sensitivity provides a general tool in estimating the relative NMR detection sensitivity for any nuclear spin at a given field strength.
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Affiliation(s)
- Hongyan Qiao
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota School of Medicine, Minneapolis, MN 55455, USA
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Xiaoliang Zhang
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota School of Medicine, Minneapolis, MN 55455, USA
| | - Xiao-Hong Zhu
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota School of Medicine, Minneapolis, MN 55455, USA
| | - Fei Du
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota School of Medicine, Minneapolis, MN 55455, USA
| | - Wei Chen
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota School of Medicine, Minneapolis, MN 55455, USA
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455, USA
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Forlenza OV, Schaeffer EL, Gattaz WF. The role of phospholipase A2 in neuronal homeostasis and memory formation: implications for the pathogenesis of Alzheimer's disease. J Neural Transm (Vienna) 2006; 114:231-8. [PMID: 17131232 DOI: 10.1007/s00702-006-0597-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2006] [Accepted: 10/30/2006] [Indexed: 11/28/2022]
Abstract
Phospholipase A(2) (PLA(2)) is a key enzyme in cerebral phospholipid metabolism. Preliminary post-mortem studies have shown that PLA(2) activity is decreased in frontal and parietal areas of the AD brain, which is in accordance with recent (31)P-Magnetic Resonance Spectroscopy evidence of reduced phospholipid turnover in the pre-frontal cortex of moderately demented AD patients. Such abnormality may also be observed in peripheral cells, and reduced PLA(2) activity in platelet membranes of AD patients, and correlates with the severity of dementia. In rat hippocampal slices, PLA(2) has been implicated in mechanisms of synaptic plasticity. In adult rats, the stereotaxic injection of PLA(2) inhibitors in the CA1 area of hippocampus impaired, in a dose-dependent manner, the formation of short- and long-term memory. Additionally, such inhibition resulted in a reduction of the fluidity of hippocampal membranes. In primary cultures of cortical and hippocampal neurons, the inhibition of PLA(2) precluded neurite outgrowth, and the sustained inhibition of the enzyme in mature cultures lead to loss of viability. Taken together, these findings reinforce the involvement of PLA(2) enzymes in neurodevelopment and neurodegeneration processes, and further suggest that reduced PLA(2) activity, probably reducing membrane phospholipids breakdown, may contribute to the memory impairment in AD.
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Affiliation(s)
- O V Forlenza
- Laboratory of Neuroscience, Department & Institute of Psychiatry, Faculty of Medicine, University of São Paulo, São Paulo, Brazil
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27
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Maurer K, Hoyer S. Alois Alzheimer revisited: differences in origin of the disease carrying his name. J Neural Transm (Vienna) 2006; 113:1645-58. [PMID: 17053872 DOI: 10.1007/s00702-006-0592-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2006] [Accepted: 09/22/2006] [Indexed: 11/26/2022]
Abstract
Based on the means of his time, Alois Alzheimer supposed that the disease, later carrying his name, is a disease of older age, and that the pathomorphological structures he described are due to disturbances in brain metabolism. In this contribution, it is discussed which cellular metabolic abnormalities may be representative for age-related sporadic Alzheimer disease (SAD) the predominant form of SAD in contrast to the very rare hereditary early-onset form. In focus are disturbances in glucose/energy metabolism which involve the deficits in acetylcholine, cholesterol and UDP-N-acetylglucosamine beside ATP. Another leading abnormality is the defect in cell membrane composition. The interrelation between abnormal glucose/energy metabolism and membrane defect may be assumed to form the basis for the induction of both the perturbed metabolism of the amyloid precursor protein leading to increased formation of beta-amyloid and hyperphosphorylation of tau-protein destroying cell structures. Alois Alzheimer may have been so prescient to assume most of this 100 years ago.
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Affiliation(s)
- K Maurer
- Clinic for Psychiatry, University of Frankfurt, Frankfurt/Main, Germany
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28
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Schaeffer EL, Gattaz WF. Inhibition of calcium-independent phospholipase A2 activity in rat hippocampus impairs acquisition of short- and long-term memory. Psychopharmacology (Berl) 2005; 181:392-400. [PMID: 15830227 DOI: 10.1007/s00213-005-2256-9] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2005] [Accepted: 02/14/2005] [Indexed: 10/25/2022]
Abstract
RATIONALE Phospholipase A(2) (PLA(2)) is a family of enzymes that cleave membrane phospholipids generating important lipid mediators in signal transduction. In rat hippocampal slices, both intracellular cytosolic Ca(2+)-dependent PLA(2) (cPLA(2)) and Ca(2+)-independent PLA(2) (iPLA(2)) have been implicated in mechanisms of synaptic plasticity underlying memory processes. In mice, intraperitoneal injections of a selective iPLA(2) inhibitor impaired spatial learning. Accordingly, reduced cPLA(2) and iPLA(2) activities were found in postmortem hippocampus of patients with Alzheimer's disease. OBJECTIVE This study investigates the effects of injections of PLA(2) inhibitors directly into rat hippocampus on the acquisition of short-term (STM) and long-term memory (LTM) of a one-trial step-down inhibitory avoidance (IA) task. METHODS Wistar rats were bilaterally implanted with cannulae in the CA1 region of the dorsal hippocampus. After surgery, the rats received bilateral injections of a vehicle, or of dual cPLA(2) and iPLA(2) inhibitors (MAFP or PACOCF(3)), or a selective iPLA(2) inhibitor (bromoenol lactone) before training in IA. The animals were tested 1.5 h (for STM) and 24 h (for LTM) after training. RESULTS Significant inhibition of iPLA(2) activity in rat hippocampus impaired acquisition of STM and LTM. Memory impairment did not result from neuronal death after iPLA(2) inhibition. Moreover, IA training per se increased significantly hippocampal PLA(2) activity. CONCLUSION The present results suggest a functional effect of hippocampal PLA(2) on the neurochemistry of memory acquisition and support the hypothesis that reduced PLA(2) activity may contribute to memory impairment in Alzheimer's disease.
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Affiliation(s)
- Evelin L Schaeffer
- Laboratory of Neuroscience (LIM-27), Department and Institute of Psychiatry, Faculty of Medicine, University of São Paulo, Brazil
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Forlenza OV, Wacker P, Nunes PV, Yacubian J, Castro CC, Otaduy MCG, Gattaz WF. Reduced phospholipid breakdown in Alzheimer's brains: a 31P spectroscopy study. Psychopharmacology (Berl) 2005; 180:359-65. [PMID: 15700180 DOI: 10.1007/s00213-005-2168-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2004] [Accepted: 12/20/2004] [Indexed: 12/13/2022]
Abstract
BACKGROUND Abnormalities of membrane phospholipid metabolism have been described in Alzheimer's disease (AD). We investigated, with the aid of (31)P magnetic resonance spectroscopy, the in vivo intracerebral availability of phosphomonoesters (PME) and phosphodiesters (PDE) in patients with AD. METHODS Eighteen outpatients with mild or moderate probable AD and 16 nondemented elderly volunteers were assessed with the Cambridge Examination for Mental Disorders of the Elderly (CAMDEX) and its cognitive subscale of the CAMDEX schedule (CAMCOG). Scans were performed on a 1.5 T magnetic resonance imager addressing a 40-cm(3) voxel in the left prefrontal cortex. Main outcome measures were mean relative peak areas of PME and PDE, which provide an estimate of membrane phospholipid metabolism. RESULTS PME resonance and the PME/PDE ratio were increased in AD patients as compared to controls (p<0.05). PME was negatively correlated with global cognitive performance as shown by the Mini-Mental State Examination (r(s)=-0.36, p=0.05) and CAMCOG scores (r(s)=-0.49, p=0.007), as well as with discrete neuropsychological functions, namely, memory (r(s)=-0.53, p=0.004), visual perception (r(s)=-0.54, p=0.003), orientation (r(s)=-0.36, p=0.05), and abstract thinking (r(s)=-0.48, p=0.01). CONCLUSIONS We provide evidence of reduced membrane phospholipid breakdown in the prefrontal cortex of mild and moderately demented AD patients. These abnormalities correlate with neuropsychological deficits that are characteristic of AD.
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Affiliation(s)
- Orestes V Forlenza
- Laboratory of Neuroscience (LIM-27) Department and Institute of Psychiatry, Faculty of Medicine, University of São Paulo, Rua Doutor Ovídio Pires de Campos 785, 05403-010, São Paulo, SP, Brazil
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30
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Hoyer S. Glucose metabolism and insulin receptor signal transduction in Alzheimer disease. Eur J Pharmacol 2004; 490:115-25. [PMID: 15094078 DOI: 10.1016/j.ejphar.2004.02.049] [Citation(s) in RCA: 314] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2003] [Revised: 12/10/2003] [Accepted: 02/27/2004] [Indexed: 12/29/2022]
Abstract
Nosologically, Alzheimer disease is not a single disorder in spite of a common clinical phenotype. Etiologically, two different types or even more exist. (1) In a minority of about 5% or less of all cases, Alzheimer disease is due to mutations of three genes, resulting in the permanent generation of betaA4. (2) The great majority (95% or more) of cases of Alzheimer disease are sporadic in origin, with old age as main risk factor, supporting the view that susceptibility genes and aging contribute to age-related sporadic Alzheimer disease. However, disturbances in the neuronal insulin signal transduction pathway may be of central pathophysiological significance. In early-onset familial Alzheimer disease, the inhibition of neuronal insulin receptor function may be due to competitive binding of amyloid beta (Abeta) to the insulin receptor. In late-onset sporadic Alzheimer disease, the neuronal insulin receptor may be desensitized by inhibition of receptor function at different sites by noradrenaline and/or cortisol, the levels of which both increase with increasing age. The consequences of the inhibition of neuronal insulin signal transduction may be largely identical to those of disturbances of oxidative energy metabolism and related metabolism, and of hyperphosphorylation of tau-protein. As far as the metabolism of amyloid precursor protein (APP) in late-onset sporadic Alzheimer disease is concerned, neuronal insulin receptor dysfunction may result in the intracellular accumulation of Abeta and in subsequent cellular damage. In this context, the desensitization of the neuronal insulin receptor in late-onset sporadic Alzheimer disease is different from that occurring in normal aging and early-onset familial Alzheimer disease. In late-onset sporadic Alzheimer disease changes in the brain are similar to those caused by non-insulin-dependent diabetes mellitus.
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Affiliation(s)
- Siegfried Hoyer
- Department of Pathology, University of Heidelberg, Im Neuenheimer Feld 220/221, 69120 Heidelberg, Germany.
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31
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Abstract
The neurophysiological basis of cognition is relatively unexplained, with most studies reporting weak relationships between cognition and measures of brain function, such as event-related potentials, brain size and cerebral blood flow. Magnetic resonance spectroscopy (MRS) is an in vivo method used to detect neurochemicals within the brain that are relevant to certain brain processes. The most widely used methods are 1H-MRS and 31P-MRS, which detect compounds that contain hydrogen and phosphorus, respectively. Recent studies have shown that the absolute concentrations or ratios of these neurochemicals, in particular N-acetyl aspartate (NAA), which is associated with neuronal viability, correlate with performance on neuropsychological tests or other measures of cognitive function in normal subjects. Many studies in adults and children have shown a relationship between neurometabolite values and cognitive status or extent of cognitive dysfunction in various neurological and neuropsychiatric disorders. We review these studies and conclude that MRS has potential applications for the study of cognitive processes in health and disease and may be used clinically for differential diagnosis, the early detection of pathology and the examination of longitudinal change.
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Affiliation(s)
- Amy J Ross
- School of Psychiatry, University of New South Wales, Kensington, New South Wales 2033, Australia.
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Hoyer S. Causes and consequences of disturbances of cerebral glucose metabolism in sporadic Alzheimer disease: therapeutic implications. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2004; 541:135-52. [PMID: 14977212 DOI: 10.1007/978-1-4419-8969-7_8] [Citation(s) in RCA: 128] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Alzheimer disease is not a single disorder. Etiologically, two different types or even diseases exist: inheritance in 5% to 10% of all Alzheimer cases versus 90% to 95% AD cases whith sporadic origin (SAD). Different susceptibility genes along with adult lifestyle risk-factors- in the case of SAD the risk factor aging- may be assumed to cause the latter disorder. There is evidence that a disturbance in the insulin signal transduction pathway may be a central and early pathophysiologic event in SAD. Both, hypercortisolemia and increased adrenergic activity, in both old age and SAD may render the function of the neuronal insulin receptor vulnerable resulting in a diminished production of ATP. The reduced availability of ATP may damage the function of the endoplasmic reticulum/Golgi apparatus/trans Golgi network generating misfolded and malfolded proteins retained in the cell. In SAD, amyloid precursor protein is found to accumulate intracellularly thus not representing the cause but a driving force in the pathogenesis of SAD. Additionally, both disturbed insulin signaling and reduced ATP forward the hyperphosphorylation of tau protein. Thus, abnormalities in oxidative brain metabolism lead to the formation of two main morphologic hallmarks of SAD: senile plaques and neurofibrillary tangles. Therefore, the therapeutic goal in SAD should be the improvement of the neuronal energy state. Findings from both basic and clinical studies showed that Ginkgo biloba extract (EGb 761) may be appropiate to approach that goal.
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Affiliation(s)
- Siegfried Hoyer
- Department of Pathochemistry and General Neurochemistry, University of Heidelberg, Im Neuenheimer Feld 220/221, Heidelberg, Germany 69120
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33
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Zakzanis KK, Graham SJ, Campbell Z. A meta-analysis of structural and functional brain imaging in dementia of the Alzheimer's type: a neuroimaging profile. Neuropsychol Rev 2003; 13:1-18. [PMID: 12691498 DOI: 10.1023/a:1022318921994] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We conducted a quantitative review of the imaging literature using meta-analytic methodology to characterize further the magnitude of hippocampal deficit in probable Alzheimer's disease (AD) and to determine whether other neuroanatomic structures in AD can better discriminate the disease from normal aging. Additionally, we parceled the discriminability of neuroanatomic structures by duration of disease to determine those structures most sensitive to AD in its early and late stages. One hundred twenty-one studies published between 1984 and 2000 met criteria for inclusion in the present analysis. In total, structural (i.e., CT and MRI) and functional (i.e., SPECT and PET) neuroimaging results from 3511 patients with AD, and 1632 normal healthy controls were recorded across meta-analyses. Our results include neuroimaging profiles for both early onset and longer duration patients with AD. In sum, these profiles yield a signature of diagnostic markers in both cortical and subcortical neuroanatomic areas. This signature is consistent with the clinical phenomenology of Alzheimer's dementia and should aid in the positive identification of AD.
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34
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Lei H, Zhu XH, Zhang XL, Ugurbil K, Chen W. In vivo 31P magnetic resonance spectroscopy of human brain at 7 T: an initial experience. Magn Reson Med 2003; 49:199-205. [PMID: 12541238 DOI: 10.1002/mrm.10379] [Citation(s) in RCA: 137] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In vivo (31)P spectra were acquired from the human primary visual cortex at 7 T. The relaxation times of the cerebral metabolites, intracellular pH, rate constant (k(f)) of the creatine kinase (CK) reaction, and nuclear Overhauser enhancement (NOE) on the detected phosphorus moieties from irradiation of the water spins were measured from normal subjects. With a 5-cm-diameter surface coil, 3D (31)P chemical shift imaging was performed with a spatial resolution of 7.5 ml and an acquisition resolution of 8 min, resulting in a signal-to-noise ratio (SNR) for phosphocreatine (PCr) resonance of 32. The apparent T(1) and T(2) of PCr measured at 7 T were 3.37 +/- 0.29 s and 132.0 +/- 12.8 ms, respectively, which were considerably longer than those of adenosine triphosphate (ATP) (T(1): 1.02-1.27 s; T(2): 25-26 ms). The NOE measured in this study was 24.3% +/- 1.6% for PCr, and 10% for ATP. The k(f) measured in the human primary visual cortex was 0.24 +/- 0.03 s(-1). The results from this study suggest that ultra-high-field strength is advantageous for performing in vivo (31)P magnetic resonance spectroscopy (MRS) in the human brain.
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Affiliation(s)
- Hao Lei
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA
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35
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Pettegrew JW, Panchalingam K, Hamilton RL, McClure RJ. Brain membrane phospholipid alterations in Alzheimer's disease. Neurochem Res 2001; 26:771-82. [PMID: 11565608 DOI: 10.1023/a:1011603916962] [Citation(s) in RCA: 206] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Studies have demonstrated alterations in brain membrane phospholipid metabolite levels in Alzheimer's disease (AD). The changes in phospholipid metabolite levels correlate with neuropathological hallmarks of the disease and measures of cognitive decline. This 31P nuclear magnetic resonance (NMR) study of Folch extracts of autopsy material reveals significant reductions in AD brain levels of phosphatidylethanolamine (PtdEtn) and phosphatidylinositol (PtdIns), and elevations in sphingomyelin (SPH) and the plasmalogen derivative of PtdEtn. In the superior temporal gyrus, there were additional reductions in the levels of diphosphatidylglycerol (DPG) and phosphatidic acid (PtdA). The findings are present in 3/3 as well as 3/4 and 4/4 apolipoprotein E (apoE) genotypes. The AD findings do not appear to reflect non-specific neurodegeneration or the presence of gliosis. The present findings could possibly contribute to an abnormal membrane repair in AD brains which ultimately results in synaptic loss and the aggregation of A beta peptide.
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Affiliation(s)
- J W Pettegrew
- Department of Psychiatry. School of Medicine, University of Pittsburgh, Pennsylvania, USA.
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36
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Chen JG, Charles HC, Barboriak DP, Doraiswamy PM. Magnetic resonance spectroscopy in Alzheimer's disease: focus on N-acetylaspartate. ACTA NEUROLOGICA SCANDINAVICA. SUPPLEMENTUM 2001; 176:20-6. [PMID: 11261801 DOI: 10.1034/j.1600-0404.2000.00303.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This paper reviews published post-mortem brain and in-vivo proton magnetic resonance spectroscopy (1H-MRS) studies in Alzheimer's disease (AD) and focuses on the emerging role of N-acetylaspartate (NAA) as a prognostic marker of neuronal function. Post-mortem brain studies have reported significantly lower NAA levels in AD brains than in control brains, and some have correlated the low levels with neuropathological findings (i.e. amyloid plaques and neurofibrillary tangles). Similarly, almost all published in-vivo studies have reported lower NAA levels in AD patients compared to elderly controls. While some studies have found changes in metabolite levels that were considered useful for the diagnosis of AD, most have found that 1H-MRS provided little or no advantages over other, more common diagnostic tools. Instead, recent studies in AD and other neuropsychiatric disorders suggest that NAA may be more useful as a prognostic marker for monitoring neurodegeneration, stabilization, or improvement, and for evaluating therapeutic response to novel drugs.
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Affiliation(s)
- J G Chen
- Department of Psychiatry, Duke University of Medical Center, Durham, NC 27710, USA
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37
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Albers DS, Beal MF. Mitochondrial dysfunction and oxidative stress in aging and neurodegenerative disease. JOURNAL OF NEURAL TRANSMISSION. SUPPLEMENTUM 2001; 59:133-54. [PMID: 10961426 DOI: 10.1007/978-3-7091-6781-6_16] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A major risk factor for neurodegenerative diseases such as Parkinson's disease (PD), Huntington's disease (HD), amyotrophic lateral sclerosis (ALS), Alzheimer's disease (AD) and progressive supranuclear palsy (PSP) is aging. Two processes that have been implicated in aging are free radical-induced oxidative damage and mitochondrial dysfunction. A progressive impairment of mitochondrial function and/or increased oxidative damage has been suggested to play critical roles in the pathogenesis of these neurodegenerative diseases. For example, decreased complex I activity, increased oxidative damage and altered activities of antioxidant defense enzymes have been demonstrated in PD. In AD, decrements in complex IV activity and increased oxidative damage have been reported. Reductions in complex II activity, increased cortical lactate levels and oxidative damage have been described in HD. Some familial ALS cases are associated with mutations in the gene for Cu,Zn superoxide dismutase (SOD1) while increased oxidative damage is observed in sporadic ALS. Studies in PSP have demonstrated regionally specific reductions in brain and muscle mitochondrial function, hypofrontality and increased oxidative damage. Altogether, the age-dependent onset and progressive course of these neurodegenerative diseases may ultimately highlight an association between aging, mitochondrial impairment and oxidative stress.
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Affiliation(s)
- D S Albers
- Department of Neurology and Neuroscience, Weill Medical College of Cornell University, New York, NY 10021, USA
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38
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Abstract
There is a large body of evidence showing both metabolic defects and oxidative damage in Alzheimer's disease. Studies of cybrid cell lines show reduced cytochrome oxidase. There is also substantial evidence for a defect in alpha-ketoglutarate dehydrogenase. It is therefore possible that therapeutic strategies to improve brain metabolism or ameliorate oxidative damage might be useful in treating Alzheimer's disease.
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Affiliation(s)
- M F Beal
- Department of Neurology and Neuroscience, Weill Medical College of Cornell University and New York Presbyterian Hospital, 525 East 68th Street, Room F610, New York, New York 10021, USA.
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39
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Hetherington HP, Spencer DD, Vaughan JT, Pan JW. Quantitative (31)P spectroscopic imaging of human brain at 4 Tesla: assessment of gray and white matter differences of phosphocreatine and ATP. Magn Reson Med 2001; 45:46-52. [PMID: 11146485 DOI: 10.1002/1522-2594(200101)45:1<46::aid-mrm1008>3.0.co;2-n] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This report describes the implementation and application of a multicompartment analysis of (31)P spectroscopic imaging data to determine the tissue-specific heterogeneities in metabolite content in the human brain and surrounding tissue. Using this information and a multicompartment regression analysis the phosphocreatine and ATP content of "pure" cerebral gray and white matter, the cerebellum, and skeletal muscle was determined in a group of 10 healthy volunteers. The data were converted to mM units using previously reported values for the T(1)s of phosphocreatine and ATP at 4 T, the water content of human brain, and an external reference for absolute quantification. The phosphocreatine concentration in cerebral gray and white matter, the cerebellum, and skeletal muscle was 3.53 +/- 0.33, 3.33 +/- 0.37, 3.75 +/- 0.66, and 25.8 +/- 2.3 mM, respectively. The ATP concentration in cerebral gray and white matter, the cerebellum, and skeletal muscle was 2.19 +/- 0.33, 3.41 +/- 0.33, 1.75 +/- 0.58, and 8.5 +/- 1.9 mM, respectively. Magn Reson Med 45:46-52, 2001.
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Affiliation(s)
- H P Hetherington
- Medical Department, Brookhaven National Laboratory, Upton, New York, USA.
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40
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Hsu YY, Du AT, Schuff N, Weiner MW. Magnetic resonance imaging and magnetic resonance spectroscopy in dementias. J Geriatr Psychiatry Neurol 2001; 14:145-66. [PMID: 11563438 PMCID: PMC1857299 DOI: 10.1177/089198870101400308] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This article reviews recent studies of magnetic resonance imaging and magnetic resonance spectroscopy in dementia, including Alzheimer's disease, frontotemporal dementia, dementia with Lewy bodies, idiopathic Parkinson's disease, Huntington's disease, and vascular dementia. Magnetic resonance imaging and magnetic resonance spectroscopy can detect structural alteration and biochemical abnormalities in the brain of demented subjects and may help in the differential diagnosis and early detection of affected individuals, monitoring disease progression, and evaluation of therapeutic effect.
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Affiliation(s)
- Y Y Hsu
- Magnetic Resonance Unit, Department of Veterans Affairs Medical Center, San Francisco 94121, USA
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41
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Yao FS, Caserta MT, Wyrwicz AM. In vitro 1H and 31P NMR spectroscopic evidence of multiple aberrant biochemical pathways in murine trisomy 16 brain development. Int J Dev Neurosci 2000; 18:833-41. [PMID: 11154853 DOI: 10.1016/s0736-5748(00)00043-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Nuclear magnetic resonance (NMR) spectroscopy was used to evaluate cytosolic compounds and membrane phospholipids simultaneously in trisomy 16 (Ts16) and euploid (control) murine brain at fetal day 15 in order to examine the cellular biochemistry that underlies the neurodevelopmental consequences of chromosome triplication in this model of Down syndrome (DS). Proton NMR spectroscopic analysis of brain tissue extracts demonstrated decreased levels of choline and increased levels of myo-inositol (MI) in Ts16 brains compared with control. These data are consistent with the cholinergic deficits and elevated MI levels previously described in Ts16. Compared with euploid brains. Ts16 brains also possess higher levels of creatine, adenosine, and tyrosine. Increased levels of MI and creatine, compounds that are localized to glia, imply abnormalities in the trophic environment of Ts16 brain. Phosphorus NMR spectroscopic analysis of extracts further revealed elevated levels of anionic phospholipid membrane components, such as phosphatidylinositol (PtdIno) and phosphatidylethanolamine, in Ts16 brains. Since these compounds are confined to the inner leaflet of the membrane, the findings suggest that membrane composition is altered specifically in the cytosolic bilayer at this stage. Together our proton and phosphorus NMR spectroscopic results indicate that multiple biochemical pathways are affected in Ts16 brain development. Understanding the effects of these aberrations may elucidate the processes that lead to neural dysfunction and Alzheimer's disease (AD) neuropathology in DS individuals.
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Affiliation(s)
- F S Yao
- Department of Psychiatry and Behavioral Sciences, Northwestern University Medical School, Chicago, IL 60611, USA.
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42
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Pettegrew JW, Klunk WE, Panchalingam K, McClure RJ, Stanley JA. Molecular insights into neurodevelopmental and neurodegenerative diseases. Brain Res Bull 2000; 53:455-69. [PMID: 11137004 DOI: 10.1016/s0361-9230(00)00376-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Magnetic resonance spectroscopy (MRS) is a non-invasive physical technique that is routinely used to determine the quantity and structure of organic molecules in solution. Technical advances that have expanded the usefulness of this technique include: (1) high resolution MRS to identify and quantify individual molecules present in complex mixtures of tissue extracts; (2) in vivo MRS techniques to non-invasively monitor metabolites in humans; (3) structure determination of proteins of moderate size; and (4) improved structure characterization of solids and liquid crystals, such as the detection of phase changes in membranes. The focus of this review is on the first two technical advances mentioned above. The strengths of MRS as a research tool to investigate molecular alterations in disease states include ease of sample preparation, minimum sample manipulation, avoidance of the preparation of derivatives, and the ability to analyze an unfractionated sample. The strengths of MRS in the clinic are its ability to measure neuronal metabolite levels non-invasively in humans and its potential for disease diagnosis, monitoring disease progression, and assessing the efficacy of experimental therapies.
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Affiliation(s)
- J W Pettegrew
- Department of Psychiatry, School of Medicine, Neurophysics Laboratory, University of Pittsburgh, Pittsburgh, PA 15213, USA.
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43
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Abstract
The goal of this review is to present a comprehensive survey of the many intriguing facets of creatine (Cr) and creatinine metabolism, encompassing the pathways and regulation of Cr biosynthesis and degradation, species and tissue distribution of the enzymes and metabolites involved, and of the inherent implications for physiology and human pathology. Very recently, a series of new discoveries have been made that are bound to have distinguished implications for bioenergetics, physiology, human pathology, and clinical diagnosis and that suggest that deregulation of the creatine kinase (CK) system is associated with a variety of diseases. Disturbances of the CK system have been observed in muscle, brain, cardiac, and renal diseases as well as in cancer. On the other hand, Cr and Cr analogs such as cyclocreatine were found to have antitumor, antiviral, and antidiabetic effects and to protect tissues from hypoxic, ischemic, neurodegenerative, or muscle damage. Oral Cr ingestion is used in sports as an ergogenic aid, and some data suggest that Cr and creatinine may be precursors of food mutagens and uremic toxins. These findings are discussed in depth, the interrelationships are outlined, and all is put into a broader context to provide a more detailed understanding of the biological functions of Cr and of the CK system.
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Affiliation(s)
- M Wyss
- F. Hoffmann-La Roche, Vitamins and Fine Chemicals Division, Basel, Switzerland.
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44
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Moore CM, Frederick BB, Renshaw PF. Brain biochemistry using magnetic resonance spectroscopy: relevance to psychiatric illness in the elderly. J Geriatr Psychiatry Neurol 2000; 12:107-17. [PMID: 10593699 DOI: 10.1177/089198879901200304] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Magnetic resonance spectroscopy (MRS) allows for the noninvasive study of cerebral biochemistry. It has been used to investigate cerebral metabolic changes associated with mental illness in vivo and in vitro. In this review, we will discuss the application of MRS to psychiatric illness in the elderly. Following a brief description of the basic principles of MRS, the use of phosphorus (31P) and proton (1H) MRS to enable a better understanding of normal brain aging, dementia (Alzheimer's disease, multiple subcortical infarct dementia, Down syndrome, frontotemporal dementia, vascular dementia, age-associated memory impairment, and other dementias), major depression, and electroconvulsive therapy is detailed.
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Affiliation(s)
- C M Moore
- Brain Imaging Center, McLean Hospital, Belmont, Massachusetts 02478, USA
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45
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Hu MT, Taylor-Robinson SD, Chaudhuri KR, Bell JD, Labbé C, Cunningham VJ, Koepp MJ, Hammers A, Morris RG, Turjanski N, Brooks DJ. Cortical dysfunction in non-demented Parkinson's disease patients: a combined (31)P-MRS and (18)FDG-PET study. Brain 2000; 123 ( Pt 2):340-52. [PMID: 10648441 DOI: 10.1093/brain/123.2.340] [Citation(s) in RCA: 150] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Regional cerebral phosphorus-31 magnetic resonance spectroscopy ((31)P-MRS) was performed in 10 non- demented Parkinson's disease patients and nine age-matched control subjects. Five of the patients undergoing (31)P-MRS and four additional Parkinson's disease patients had cerebral 2-[(18)F]fluoro-2-deoxy-D-glucose PET ((18)FDG-PET), the results of which were compared with those of eight age-matched control subjects. All Parkinson's disease patients underwent neuropsychological testing including performance and verbal subtests of the Wechsler Adult Intelligence Scale-Revised, Boston Naming Test, Controlled Oral Word Association test (FAS Test) and California Learning Test to exclude clinical dementia. (31)P MR spectra from right and left temporo-parietal cortex, occipital cortex and a central voxel incorporating basal ganglia and brainstem were obtained. (31)P MR peak area ratios of signals from phosphomonoesters (PMEs), inorganic phosphate (P(i)), phosphodiesters (PDEs), alpha-ATP, gamma-ATP and phosphocreatine (PCr) relative to beta-ATP were measured. Relative percentage peak areas of PMEs, P(i), PDEs, PCr, and alpha-, beta- and gamma-ATP signals were also measured with respect to the total (31)P-MRS signal. Significant bilateral increases in the P(i)/beta-ATP ratio were found in temporoparietal cortex (P = 0.002 right and P = 0.014 left cortex) for the non-demented Parkinson's disease patients compared with controls. In the right temporoparietal cortex, there was also a significant increase in the mean relative percentage P(i) (P = 0.001). (18)FDG-PET revealed absolute bilateral reductions in glucose metabolism after partial volume effect correction in posterior parietal and temporal cortical grey matter (P < 0.01 and P < 0.05, respectively) for the Parkinson's disease group, using both volume of interest analysis and statistical parametric mapping. There were significant correlations between right temporoparietal P(i)/beta-ATP ratios and estimated reductions in performance IQ (r = 0.96, P < 0.001). Left temporoparietal P(i)/beta-ATP ratios correlated with full scale IQ and verbal IQ (r = -0.82, P = 0.006, r = -0.86, P = 0.003, respectively). In summary, temporoparietal cortical hypometabolism was seen in non-demented Parkinson's disease patients with both (31)P-MRS and (18)FDG-PET, suggesting that both glycolytic and oxidative pathways are impaired. This dysfunction may reflect either the presence of primary cortical pathology or deafferentation of striato-cortical projections. (31)P-MRS and (18)FDG-PET may both provide useful predictors of future cognitive impairment in a subset of Parkinson's disease patients who go on to develop dementia.
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Affiliation(s)
- M T Hu
- Medical Research Council Cyclotron Unit, Department of Neurosciences, Guys, King's, St Thomas's Hospital Medical School and Institute of Psychiatry, London, UK
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46
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Barbiroli B, Martinelli P, Patuelli A, Lodi R, Iotti S, Cortelli P, Montagna P. Phosphorus magnetic resonance spectroscopy in multiple system atrophy and Parkinson's disease. Mov Disord 1999; 14:430-5. [PMID: 10348465 DOI: 10.1002/1531-8257(199905)14:3<430::aid-mds1007>3.0.co;2-s] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
We performed in vivo phosphorus magnetic resonance spectroscopy on the occipital lobes of 15 patients with multiple system atrophy (MSA; eight with olivopontocerebellar atrophy [OPCA] and seven with the striatonigral degeneration variant [SND]), 13 patients with idiopathic Parkinson's disease (PD), and 16 age-matched healthy subjects. The MSA group showed significantly reduced phosphocreatine (PCr), increased inorganic phosphate (Pi), and unchanged cytosolic free [Mg2+], and pH. We did not find any significant difference between the OPCA and SND variants. However, patients with PD showed significantly increased content of Pi, decreased cytosolic free [Mg2+], and unchanged [PCr] and pH. Comparing the MSA and PD groups, [PCr] was significantly lower in MSA than in PD, whereas cytosolic free [Mg2+] was significantly lower in PD. Despite a certain degree of overlap of [PCr] and [Mg2+] values between the two groups, by considering both variables at the same time it was possible to classify correctly 93% of cases by discriminant analysis. We conclude that phosphorus magnetic resonance spectroscopy discloses abnormal phosphate metabolite and ion contents in both MSA and PD, respectively, and may provide noninvasive diagnostic help to differentiate MSA from PD.
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Affiliation(s)
- B Barbiroli
- Biochimica Clinica, Dipartimento di Medicina Clinica e Biotecnologia Applicata D. Campanacci, Università di Bologna, Italy
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47
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Fiskum G, Murphy AN, Beal MF. Mitochondria in neurodegeneration: acute ischemia and chronic neurodegenerative diseases. J Cereb Blood Flow Metab 1999; 19:351-69. [PMID: 10197505 DOI: 10.1097/00004647-199904000-00001] [Citation(s) in RCA: 272] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- G Fiskum
- Department of Anesthesiology, University of Maryland School of Medicine, Baltimore 21201, USA
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48
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Klunk WE, Panchalingam K, McClure RJ, Stanley JA, Pettegrew JW. Metabolic alterations in postmortem Alzheimer's disease brain are exaggerated by Apo-E4. Neurobiol Aging 1998; 19:511-5. [PMID: 10192209 DOI: 10.1016/s0197-4580(98)00105-5] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Alterations in phospholipid metabolites are a characteristic abnormality of Alzheimer's disease (AD). Many of these alterations have been demonstrated by magnetic resonance spectroscopy (MRS) studies of postmortem tissue. Phosphodiesters appear to be elevated late in the disease and phosphomonoesters appear to be elevated early in the disease and then decrease. Second to aging, the most robust risk factor for AD identified to date is the presence of the E4 allele of apolipoprotein-E (Apo-E). Because apolipoproteins are intimately involved in lipid metabolism, this study was performed to determine if the presence of the Apo-E4 allele affects the abnormalities in phospholipid metabolites in AD brain. Perchloric acid extracts from 12 Apo-E 3/3, 31 3/4, 6 4/4 AD brains and 5 Apo-E 3/3 control brains were studied by both proton magnetic resonance spectroscopy and phosphorus-31 magnetic resonance spectroscopy. When the E4-positive AD samples were compared with the 3/3 AD samples, an exaggeration in both phosphomonoester and phosphodiester abnormalities was observed. The decrease in N-acetyl-L-aspartate (NAA) was also exaggerated. These results suggest membrane phospholipid metabolite alterations observed in AD are more severe in the presence of the Apo-E4 allele.
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Affiliation(s)
- W E Klunk
- Department of Psychiatry, Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, PA 15261, USA.
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49
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Abstract
A potential pivotal role for mitochondrial dysfunction in neurodegenerative diseases is gaining increasing acceptance. Mitochondrial dysfunction leads to a number of deleterious consequences including impaired calcium buffering, generation of free radicals, activation of the mitochondrial permeability transition and secondary excitotoxicity. Neurodegenerative diseases of widely disparate genetic etiologies may share mitochondrial dysfunction as a final common pathway. Recent studies using cybrid cell lines suggest that sporadic Alzheimer's disease is associated with a deficiency of cytochrome oxidase. Friedreich's ataxia is caused by an expanded GAA repeat resulting in dysfunction of frataxin, a nuclear encoded mitochondrial protein involved in mitochondrial iron transport. This results in increased mitochondrial iron and oxidative damage. Familial amyotrophic lateral sclerosis is associated with point mutations in superoxide dismutase, which may lead to increased generation of free radicals and thereby contribute to mitochondrial dysfunction. Huntington's disease (HD) is caused by an expanded CAG repeat in an unknown protein termed huntingtin. The means by which this leads to energy impairment is unclear, however studies in both HD patients and a transgenic mouse model show evidence of bioenergetic defects. Mitochondrial dysfunction leads to oxidative damage which is well documented in several neurodegenerative diseases. Therapeutic approaches include methods to buffer intracellular ATP and to scavenge free radicals.
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Affiliation(s)
- M F Beal
- Neurology Service/WRN 408, Massachusetts General Hospital and Harvard Medical School, 32 Fruit Street, Boston, MA 02114, USA.
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50
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Abstract
Aging influences cerebrovascular disease expression by a variety of mechanisms. Age-related changes in cerebral autoregulation, cellular metabolism, the blood-brain barrier, and autonomic function may leave the cerebrovascular system vulnerable to injury. Certain cerebrovascular disease, such as atrial fibrillation, watershed infarctions, carotid artery atherosclerosis, cerebral hemorrhages, subdural hematomas, and transient global amnesia manifest in the elderly. Vascular dementia and white matter disease are better understood with newer neuroimaging studies, careful neuropsychological and histopathologic examinations. Atherosclerosis and cerebral amyloid angiopathy may have larger roles than previously understood in Alzheimer's disease.
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Affiliation(s)
- J Y Choi
- Department of Neurology, Barnes-Jewish Hospital, Washington University, St. Louis, Missouri 63110-1093, USA
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