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Liu X, Lv Z, Huang Q, Lei Y, Liu H, Xu P. The Role of Oligodendrocyte Lineage Cells in the Pathogenesis of Alzheimer's Disease. Neurochem Res 2025; 50:72. [PMID: 39751972 DOI: 10.1007/s11064-024-04325-3] [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: 07/29/2024] [Revised: 10/06/2024] [Accepted: 12/18/2024] [Indexed: 01/04/2025]
Abstract
Alzheimer's disease (AD) is a central nervous system degenerative disease with a stealthy onset and a progressive course characterized by memory loss, cognitive dysfunction, and abnormal psychological and behavioral symptoms. However, the pathogenesis of AD remains elusive. An increasing number of studies have shown that oligodendrocyte progenitor cells (OPCs) and oligodendroglial lineage cells (OLGs), especially OPCs and mature oligodendrocytes (OLGs), which are derived from OPCs, play important roles in the pathogenesis of AD. OLGs function mainly by myelinating axons, transmitting electrical signals, and regulating neural development. In addition to myelin, OPCs and OLGs can also participate in AD pathogenesis in other ways. This review summarizes the mechanisms by which OPCs and OLGs affect myelin formation, oxidative stress, neuroinflammation, the blood-brain barrier, synaptic function, and amyloid-beta protein and further elucidates the mechanisms by which oligodendrocyte lineage cells participate in AD pathogenesis and treatment, which is highly important for clarifying the pathogenesis of AD, clinical treatment, and prevention.
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Affiliation(s)
- Xiaodong Liu
- Department of Neurology, Affiliated Hospital of Zunyi Medical University, Zunyi, China
- Department of Neurology, China Guihang Group 302 Hospital, Anshun, China
| | - Zhengxiang Lv
- Department of Neurology, Affiliated Hospital of Zunyi Medical University, Zunyi, China
- Department of Neurology, China Guihang Group 302 Hospital, Anshun, China
| | - Qin Huang
- Department of Neurology, Affiliated Hospital of Zunyi Medical University, Zunyi, China
| | - Yihui Lei
- Department of Neurology, Affiliated Hospital of Zunyi Medical University, Zunyi, China
| | - Haijun Liu
- Department of Neurology, Affiliated Hospital of Zunyi Medical University, Zunyi, China
| | - Ping Xu
- Department of Neurology, Affiliated Hospital of Zunyi Medical University, Zunyi, China.
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Ahmed M, Lai AY, Hill ME, Ribeiro JA, Amiraslani A, McLaurin J. Obesity differentially effects the somatosensory cortex and striatum of TgF344-AD rats. Sci Rep 2024; 14:7235. [PMID: 38538727 PMCID: PMC10973391 DOI: 10.1038/s41598-024-57953-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Accepted: 03/23/2024] [Indexed: 04/04/2024] Open
Abstract
Lifestyle choices leading to obesity, hypertension and diabetes in mid-life contribute directly to the risk of late-life Alzheimer's disease (AD). However, in late-life or in late-stage AD conditions, obesity reduces the risk of AD and disease progression. To examine the mechanisms underlying this paradox, TgF344-AD rats were fed a varied high-carbohydrate, high-fat (HCHF) diet to induce obesity from nine months of age representing early stages of AD to twelve months of age in which rats exhibit the full spectrum of AD symptomology. We hypothesized regions primarily composed of gray matter, such as the somatosensory cortex (SSC), would be differentially affected compared to regions primarily composed of white matter, such as the striatum. We found increased myelin and oligodendrocytes in the somatosensory cortex of rats fed the HCHF diet with an absence of neuronal loss. We observed decreased inflammation in the somatosensory cortex despite increased AD pathology. Compared to the somatosensory cortex, the striatum had fewer changes. Overall, our results suggest that the interaction between diet and AD progression affects myelination in a brain region specific manner such that regions with a lower density of white matter are preferentially affected. Our results offer a possible mechanistic explanation for the obesity paradox.
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Affiliation(s)
- Minhal Ahmed
- Biological Sciences, Sunnybrook Research Institute, Toronto, ON, M4N 3M5, Canada
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Aaron Y Lai
- Biological Sciences, Sunnybrook Research Institute, Toronto, ON, M4N 3M5, Canada
| | - Mary E Hill
- Biological Sciences, Sunnybrook Research Institute, Toronto, ON, M4N 3M5, Canada
| | - Jessica A Ribeiro
- Biological Sciences, Sunnybrook Research Institute, Toronto, ON, M4N 3M5, Canada
| | - Ashley Amiraslani
- Biological Sciences, Sunnybrook Research Institute, Toronto, ON, M4N 3M5, Canada
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - JoAnne McLaurin
- Biological Sciences, Sunnybrook Research Institute, Toronto, ON, M4N 3M5, Canada.
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada.
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Ahmed M, Lai AY, Hill ME, Ribeiro JA, Amiraslani A, McLaurin J. Obesity differentially effects the somatosensory cortex and striatum of TgF344-AD rats. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.22.576454. [PMID: 38545621 PMCID: PMC10970715 DOI: 10.1101/2024.01.22.576454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Lifestyle choices leading to obesity, hypertension and diabetes in mid-life contribute directly to the risk of late-life Alzheimer's disease (AD). However, in late-life or in late-stage AD conditions, obesity reduces the risk of AD and disease progression. To examine the mechanisms underlying this paradox, TgF344-AD rats were fed a varied high-carbohydrate, high-fat (HCHF) diet to induce obesity from nine months of age representing early stages of AD to twelve months of age in which rats exhibit the full spectrum of AD symptomology. We hypothesized regions primarily composed of gray matter, such as the somatosensory cortex (SSC), would be differentially affected compared to regions primarily composed of white matter, such as the striatum. We found increased myelin and oligodendrocytes in the somatosensory cortex of rats fed the HCHF diet with an absence of neuronal loss. We observed decreased inflammation in the somatosensory cortex despite increased AD pathology. Compared to the somatosensory cortex, the striatum had fewer changes. Overall, our results suggest that the interaction between diet and AD progression affects myelination in a brain region specific manner such that regions with a lower density of white matter are preferentially effected. Our results offer a possible mechanistic explanation for the obesity paradox.
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Wang N, Wang M, Jeevaratnam S, Rosenberg C, Ikezu TC, Shue F, Doss SV, Alnobani A, Martens YA, Wren M, Asmann YW, Zhang B, Bu G, Liu CC. Opposing effects of apoE2 and apoE4 on microglial activation and lipid metabolism in response to demyelination. Mol Neurodegener 2022; 17:75. [PMID: 36419137 PMCID: PMC9682675 DOI: 10.1186/s13024-022-00577-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 10/21/2022] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Abnormal lipid accumulation has been recognized as a key element of immune dysregulation in microglia whose dysfunction contributes to neurodegenerative diseases. Microglia play essential roles in the clearance of lipid-rich cellular debris upon myelin damage or demyelination, a common pathogenic event in neuronal disorders. Apolipoprotein E (apoE) plays a pivotal role in brain lipid homeostasis; however, the apoE isoform-dependent mechanisms regulating microglial response upon demyelination remain unclear. METHODS To determine how apoE isoforms impact microglial response to myelin damage, 2-month-old apoE2-, apoE3-, and apoE4-targeted replacement (TR) mice were fed with normal diet (CTL) or 0.2% cuprizone (CPZ) diet for four weeks to induce demyelination in the brain. To examine the effects on subsequent remyelination, the cuprizone diet was switched back to regular chow for an additional two weeks. After treatment, brains were collected and subjected to immunohistochemical and biochemical analyses to assess the myelination status, microglial responses, and their capacity for myelin debris clearance. Bulk RNA sequencing was performed on the corpus callosum (CC) to address the molecular mechanisms underpinning apoE-mediated microglial activation upon demyelination. RESULTS We demonstrate dramatic isoform-dependent differences in the activation and function of microglia upon cuprizone-induced demyelination. ApoE2 microglia were hyperactive and more efficient in clearing lipid-rich myelin debris, whereas apoE4 microglia displayed a less activated phenotype with reduced clearance efficiency, compared with apoE3 microglia. Transcriptomic profiling revealed that key molecules known to modulate microglial functions had differential expression patterns in an apoE isoform-dependent manner. Importantly, apoE4 microglia had excessive buildup of lipid droplets, consistent with an impairment in lipid metabolism, whereas apoE2 microglia displayed a superior ability to metabolize myelin enriched lipids. Further, apoE2-TR mice had a greater extent of remyelination; whereas remyelination was compromised in apoE4-TR mice. CONCLUSIONS Our findings provide critical mechanistic insights into how apoE isoforms differentially regulate microglial function and the maintenance of myelin dynamics, which may inform novel therapeutic avenues for targeting microglial dysfunctions in neurodegenerative diseases.
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Affiliation(s)
- Na Wang
- grid.417467.70000 0004 0443 9942Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224 USA
| | - Minghui Wang
- grid.59734.3c0000 0001 0670 2351Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029 USA
| | - Suren Jeevaratnam
- grid.417467.70000 0004 0443 9942Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224 USA
| | - Cassandra Rosenberg
- grid.417467.70000 0004 0443 9942Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224 USA
| | - Tadafumi C. Ikezu
- grid.417467.70000 0004 0443 9942Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224 USA
| | - Francis Shue
- grid.417467.70000 0004 0443 9942Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224 USA
| | - Sydney V. Doss
- grid.417467.70000 0004 0443 9942Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224 USA
| | - Alla Alnobani
- grid.417467.70000 0004 0443 9942Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224 USA
| | - Yuka A. Martens
- grid.417467.70000 0004 0443 9942Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224 USA
| | - Melissa Wren
- grid.417467.70000 0004 0443 9942Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224 USA
| | - Yan W. Asmann
- grid.417467.70000 0004 0443 9942Division of Biomedical Statistics and Informatics, Department of Health Sciences Research, Mayo Clinic, Jacksonville, FL 32224 USA
| | - Bin Zhang
- grid.59734.3c0000 0001 0670 2351Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029 USA
| | - Guojun Bu
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, USA.
| | - Chia-Chen Liu
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, USA.
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Drinkwater E, Davies C, Spires-Jones TL. Potential neurobiological links between social isolation and Alzheimer's disease risk. Eur J Neurosci 2022; 56:5397-5412. [PMID: 34184343 DOI: 10.1111/ejn.15373] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 06/21/2021] [Accepted: 06/22/2021] [Indexed: 12/14/2022]
Abstract
It is estimated that 40% of dementia cases could be prevented by modification of lifestyle factors that associate with disease risk. One of these potentially modifiable lifestyle factors is social isolation. In this review, we discuss what is known about associations between social isolation and Alzheimer's disease, the most common cause of dementia. This is particularly relevant in the time of the COVID-19 pandemic when social isolation has been enforced with potential emerging negative impacts on cognition. While there are neurobiological mechanisms emerging that may account for the observed epidemiological associations between social isolation and Alzheimer's disease, more fundamental research is needed to fully understand the brain changes induced by isolation that may make people vulnerable to disease.
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Affiliation(s)
| | - Caitlin Davies
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.,Translational Neuroscience PhD Programme, University of Edinburgh, Edinburgh, UK.,UK Dementia Research Institute, University of Edinburgh, Edinburgh, UK
| | - Tara L Spires-Jones
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.,UK Dementia Research Institute, University of Edinburgh, Edinburgh, UK
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Proteostasis Deregulation in Neurodegeneration and Its Link with Stress Granules: Focus on the Scaffold and Ribosomal Protein RACK1. Cells 2022; 11:cells11162590. [PMID: 36010666 PMCID: PMC9406587 DOI: 10.3390/cells11162590] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 08/09/2022] [Accepted: 08/17/2022] [Indexed: 12/12/2022] Open
Abstract
The role of protein misfolding, deposition, and clearance has been the dominant topic in the last decades of investigation in the field of neurodegeneration. The impairment of protein synthesis, along with RNA metabolism and RNA granules, however, are significantly emerging as novel potential targets for the comprehension of the molecular events leading to neuronal deficits. Indeed, defects in ribosome activity, ribosome stalling, and PQC—all ribosome-related processes required for proteostasis regulation—can contribute to triggering stress conditions and promoting the formation of stress granules (SGs) that could evolve in the formation of pathological granules, usually occurring during neurodegenerating effects. In this review, the interplay between proteostasis, mRNA metabolism, and SGs has been explored in a neurodegenerative context with a focus on Alzheimer’s disease (AD), although some defects in these same mechanisms can also be found in frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS), which are discussed here. Finally, we highlight the role of the receptor for activated C kinase 1 (RACK1) in these pathologies and note that, besides its well characterized function as a scaffold protein, it has an important role in translation and can associate to stress granules (SGs) determining cell fate in response to diverse stress stimuli.
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Guemri J, Pierre-Jean M, Brohard S, Oussada N, Horgues C, Bonnet E, Mauger F, Deleuze JF. Methylated ccfDNA from plasma biomarkers of Alzheimer's disease using targeted bisulfite sequencing. Epigenomics 2022; 14:451-468. [PMID: 35416052 DOI: 10.2217/epi-2021-0491] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Aim: Noninvasive biomarkers such as methylated ccfDNA from plasma could help to support the diagnosis of Alzheimer's disease (AD). Methods: A targeted sequencing protocol was developed to identify candidate biomarkers of AD in methylated ccfDNA extracted from plasma. Results: The authors identified differentially methylated CpGs, regions of which were the same as those identified in previous AD studies. Specifically, a differentially methylated CpG of the LHX2 gene previously identified in a plasma study of AD was replicated in the study. The MBP and DUSP22 regions have been identified in other brain studies of AD and in the authors' study. Conclusion: Although these biomarkers must be validated in other cohorts, methylated ccfDNA could be a relevant noninvasive biomarker in AD.
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Affiliation(s)
- Julien Guemri
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de Recherche en Génomique Humaine, Evry, 91057, France
| | - Morgane Pierre-Jean
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de Recherche en Génomique Humaine, Evry, 91057, France
| | - Solène Brohard
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de Recherche en Génomique Humaine, Evry, 91057, France
| | - Nouara Oussada
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de Recherche en Génomique Humaine, Evry, 91057, France
| | - Caroline Horgues
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de Recherche en Génomique Humaine, Evry, 91057, France
| | - Eric Bonnet
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de Recherche en Génomique Humaine, Evry, 91057, France
| | - Florence Mauger
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de Recherche en Génomique Humaine, Evry, 91057, France
| | - Jean-François Deleuze
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de Recherche en Génomique Humaine, Evry, 91057, France
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Zheng M, Liu Z, Mana L, Qin G, Huang S, Gong Z, Tian M, He Y, Wang P. Shenzhiling oral liquid protects the myelin sheath against Alzheimer's disease through the PI3K/Akt-mTOR pathway. JOURNAL OF ETHNOPHARMACOLOGY 2021; 278:114264. [PMID: 34082015 DOI: 10.1016/j.jep.2021.114264] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 05/22/2021] [Accepted: 05/27/2021] [Indexed: 06/12/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Shenzhiling oral liquid (SZL), a traditional Chinese medicine (TCM) compound, is firstly approved by the Chinese Food and Drug Administration (CFDA) for the treatment of mild to moderate Alzheimer's disease (AD). SZL is composed of ten Chinese herbs, and the precise therapy mechanism of its action to AD is far from fully understood. AIM OF THE STUDY The purpose of this study was to observe whether SZL is an effective therapy for amyloid-beta (Aβ)-induced myelin sheath and oligodendrocytes impairments. Notably, the primary aim was to elucidate whether and through what underlying mechanism SZL protects the myelin sheath through the PI3K/Akt-mTOR signaling pathway in Aβ42-induced OLN-93 oligodendrocytes in vitro. MATERIALS AND METHODS APP/PS1 mice were treated with SZL or donepezil continuously for three months, and Aβ42-induced oligodendrocyte OLN-93 cells mimicking AD pathogenesis of myelin sheath impairments were incubated with SZL-containing serum or with donepezil. LC-MS/MS was used to analysis the active components of SZL and SZL-containing serum. The Y maze test was administered after 3 months of treatment, and the hippocampal tissues of the APP/PS1 mice were then harvested for observation of myelin sheath and oligodendrocyte morphology. Cell viability and toxicity were assessed using CCK-8 and lactate dehydrogenase (LDH) release assays, and flow cytometry was used to measure cell apoptosis. The expression of the myelin proteins MBP, PLP, and MAG and that of Aβ42 and Aβ40 in the hippocampi of APP/PS1 mice were examined after SZL treatment. Simultaneously, the expression of p-PI3K, PI3K, p-Akt, Akt, p-mTOR, and mTOR were also examined. The expression of proteins, including CNPase, Olig2, NKX2.2, MBP, PLP, MAG, MOG, p-PI3K, PI3K, p-Akt, Akt, p-mTOR, and mTOR, was determined by immunofluorescence and Western blot, and the corresponding gene expression was evaluated by qPCR in Aβ42-induced OLN-93 oligodendrocytes. RESULTS LC-MS/MS detected a total of 126 active compounds in SZL-containing serum, including terpenoids, flavones, phenols, phenylpropanoids and phenolic acids. SZL treatment significantly improved memory and cognition in APP/PS1 mice and decreased the G-ratio of myelin sheath, alleviated myelin sheath and oligodendrocyte impairments by decreasing Aβ42 and Aβ40 accumulation and increasing the expression of myelin proteins MBP, PLP, MAG, and PI3K/Akt-mTOR signaling pathway associated protein in the hippocampi of APP/PS1 mice. SZL-containing serum also significantly reversed the OLN-93 cell injury induced by Aβ42 by increasing cell viability and enhanced the expression of MBP, PLP, MAG, and MOG. Meanwhile, SZL-containing serum facilitated the maturation and differentiation of oligodendrocytes in Aβ42-induced OLN-93 cells by heightening the expression of CNPase, Olig2 and NKX2.2. SZL-containing serum treatment also fostered the expression of p-PI3K, PI3K, p-Akt, Akt, p-mTOR, and mTOR, indicating an activating PI3K/Akt-mTOR signaling pathway in OLN-93 cells. Furthermore, the effects of SZL on myelin proteins, p-Akt, and p-mTOR were clearly inhibited by LY294002 and/or rapamycin, antagonists of PI3K and m-TOR, respectively. CONCLUSIONS Our findings indicate that SZL exhibits a neuroprotective effect on the myelin sheath by promoting the expression of myelin proteins during AD, and its mechanism of action is closely related to the activation of the PI3K/Akt-mTOR signaling pathway.
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Affiliation(s)
- Mingcui Zheng
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital, Beijing University of Chinese Medicine (BUCM), Beijing, 100700, China; Key Laboratory of Pharmacology Dongzhimen Hospital (BUCM), State Administration of Traditional Chinese Medicine, Beijing, 100700, China.
| | - Zhenhong Liu
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital, Beijing University of Chinese Medicine (BUCM), Beijing, 100700, China; Key Laboratory of Pharmacology Dongzhimen Hospital (BUCM), State Administration of Traditional Chinese Medicine, Beijing, 100700, China; Institute for Brain Disorders, Beijing University of Chinese Medicine (BUCM), Beijing, 100029, China.
| | - Lulu Mana
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital, Beijing University of Chinese Medicine (BUCM), Beijing, 100700, China; Key Laboratory of Pharmacology Dongzhimen Hospital (BUCM), State Administration of Traditional Chinese Medicine, Beijing, 100700, China; Xinjiang Medical University, Urumqi, 830011, China.
| | - Gaofeng Qin
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital, Beijing University of Chinese Medicine (BUCM), Beijing, 100700, China; Key Laboratory of Pharmacology Dongzhimen Hospital (BUCM), State Administration of Traditional Chinese Medicine, Beijing, 100700, China.
| | - Shuaiyang Huang
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital, Beijing University of Chinese Medicine (BUCM), Beijing, 100700, China; Key Laboratory of Pharmacology Dongzhimen Hospital (BUCM), State Administration of Traditional Chinese Medicine, Beijing, 100700, China.
| | - Zhuoyan Gong
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital, Beijing University of Chinese Medicine (BUCM), Beijing, 100700, China; Key Laboratory of Pharmacology Dongzhimen Hospital (BUCM), State Administration of Traditional Chinese Medicine, Beijing, 100700, China.
| | - Meijing Tian
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital, Beijing University of Chinese Medicine (BUCM), Beijing, 100700, China; Key Laboratory of Pharmacology Dongzhimen Hospital (BUCM), State Administration of Traditional Chinese Medicine, Beijing, 100700, China.
| | - Yannan He
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital, Beijing University of Chinese Medicine (BUCM), Beijing, 100700, China; Key Laboratory of Pharmacology Dongzhimen Hospital (BUCM), State Administration of Traditional Chinese Medicine, Beijing, 100700, China.
| | - Pengwen Wang
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital, Beijing University of Chinese Medicine (BUCM), Beijing, 100700, China; Key Laboratory of Pharmacology Dongzhimen Hospital (BUCM), State Administration of Traditional Chinese Medicine, Beijing, 100700, China.
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Papuć E, Rejdak K. The role of myelin damage in Alzheimer's disease pathology. Arch Med Sci 2020; 16:345-351. [PMID: 32190145 PMCID: PMC7069444 DOI: 10.5114/aoms.2018.76863] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Accepted: 04/30/2018] [Indexed: 02/07/2023] Open
Abstract
Although Alois Alzheimer described myelin disruption in Alzheimer's disease (AD) as early as in 1911, his observation has escaped the attention of researchers since that time. Alzheimer's disease has been mainly considered as a grey matter disorder; nevertheless, recent evidence suggests that myelin impairment may play an important role in AD pathology. Classical neuropathological changes in AD, e.g. the accumulation of aggregated Aβ 42 and the presence of neurofibrillary tangles, are responsible for neuronal loss, but they may also induce death of oligodendrocytes and myelin damage. There is also evidence that myelin pathology may even precede Aβ and tau pathologies in AD. The state of the art does not allow us to determine whether myelin damage is a primary or a secondary injury in AD subjects. The article presents an overview of current knowledge on the role of myelin in AD pathology and its interactions with Aβ and tau pathologies.
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Affiliation(s)
- Ewa Papuć
- Department of Neurology, Medical University of Lublin, Lublin, Poland
| | - Konrad Rejdak
- Department of Neurology, Medical University of Lublin, Lublin, Poland
- Medical Research Center, Polish Academy of Sciences, Warsaw, Poland
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FTY720 Improves Behavior, Increases Brain Derived Neurotrophic Factor Levels and Reduces α-Synuclein Pathology in Parkinsonian GM2+/- Mice. Neuroscience 2019; 411:1-10. [PMID: 31129200 DOI: 10.1016/j.neuroscience.2019.05.029] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 04/26/2019] [Accepted: 05/14/2019] [Indexed: 12/14/2022]
Abstract
Parkinson's disease (PD) is a progressive aging disorder that affects millions worldwide, thus, disease-modifying-therapies are urgently needed. PD pathology includes α-synuclein (aSyn) accumulation as synucleinopathy. Loss of GM1 gangliosides occurs in PD brain, which is modeled in GM2 synthase transgenic mice. GM2+/- mice have low, not absent GM1 and develop age-onset motor deficits, making them an excellent PD drug testing model. FTY720 (fingolimod) reduces synucleinopathy in A53T aSyn mice and motor dysfunction in 6-OHDA and rotenone PD models, but no one has tested FTY720 in mice that develop age-onset PD-like motor problems. We confirmed that GM2+/-mice had equivalent rotarod, hindlimb reflexes, and adhesive removal functions at 9 mo. From 11 mo, GM2+/- mice received oral FTY720 or vehicle 3x/week to 16 mo. As bladder problems occur in PD, we also assessed GM2+/- bladder function. This allowed us to demonstrate improved motor and bladder function in GM2+/- mice treated with FTY720. By immunoblot, FTY720 reduced levels of proNGF, a biomarker of bladder dysfunction. In humans with PD, arm swing becomes abnormal, and brachial plexus modulates arm swing. Ultrastructure of brachial plexus in wild type and GM2 transgenic mice confirmed abnormal myelination and axons in GM2 transgenics. FTY720 treated GM2+/- brachial plexus sustained myelin associated protein levels and reduced aggregated aSyn and PSer129 aSyn levels. FTY720 increases brain derived neurotrophic factor (BDNF) and we noted increased BDNF in GM2+/- brachial plexus and cerebellum, which contribute to rotarod performance. These findings provide further support for testing low dose FTY720 in patients with PD.
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Zhou CN, Chao FL, Zhang Y, Jiang L, Zhang L, Luo YM, Xiao Q, Chen LM, Tang Y. Sex Differences in the White Matter and Myelinated Fibers of APP/PS1 Mice and the Effects of Running Exercise on the Sex Differences of AD Mice. Front Aging Neurosci 2018; 10:243. [PMID: 30174598 PMCID: PMC6107833 DOI: 10.3389/fnagi.2018.00243] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 07/24/2018] [Indexed: 12/03/2022] Open
Abstract
Previous studies have suggested that changes in the white matter might play an important role in the pathogenic processes of Alzheimer's disease (AD). However, no study has investigated sex differences in these changes. Previous studies found that running exercise could delay both the decline in spatial learning and memory abilities as well as the changes in the white matter during early AD in male mice. However, whether exercise also has an effect on the changes in the white matter in female AD mice remains unknown. To address these questions, 6- and 10-month-old male and female APP/PS1 double transgenic AD mice were used. The 6-month-old male and female APP/PS1 double transgenic AD mice underwent a 4-month running exercise regime. The white matter volume and parameters of the myelinated fibers in the white matter of the 10-month-old exercised and non-exercised male and female AD mice were investigated using electron microscopy and stereological methods. There were no significant differences in the mean escape latencies between the male and female AD mice in the non-exercised groups, but after 4 months of treadmill exercise, the mean escape latencies of the female exercised AD mice had significantly shortened compared with those of the male exercised AD mice. The total white matter volume and most of the parameters of the myelinated fibers of the white matter in the female AD mice were significantly lower than those of the male AD mice. The total length of the myelinated fibers with diameters ranging from 0.6 to 0.7 μm, the axonal diameter of the myelinated fibers and the g-ratio of the myelinated fibers in the white matter of the exercised female AD mice were significantly increased compared with those of the non-exercised female AD mice. There were sex-specific differences in the white matter and myelinated fibers of white matter in the AD mice. Running exercise more effectively delayed the decline in spatial learning and memory abilities and delayed the changes in the myelinated fibers of the white matter in female transgenic mice with early AD than in male transgenic mice.
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Affiliation(s)
- Chun-Ni Zhou
- Department of Histology and Embryology, Chongqing Medical University, Chongqing, China.,Laboratory of Stem Cells and Tissue Engineering, Chongqing Medical University, Chongqing, China
| | - Feng-Lei Chao
- Department of Histology and Embryology, Chongqing Medical University, Chongqing, China.,Laboratory of Stem Cells and Tissue Engineering, Chongqing Medical University, Chongqing, China
| | - Yi Zhang
- Department of Histology and Embryology, Chongqing Medical University, Chongqing, China.,Laboratory of Stem Cells and Tissue Engineering, Chongqing Medical University, Chongqing, China
| | - Lin Jiang
- Department of Histology and Embryology, Chongqing Medical University, Chongqing, China.,Laboratory of Stem Cells and Tissue Engineering, Chongqing Medical University, Chongqing, China
| | - Lei Zhang
- Department of Histology and Embryology, Chongqing Medical University, Chongqing, China.,Laboratory of Stem Cells and Tissue Engineering, Chongqing Medical University, Chongqing, China
| | - Yan-Min Luo
- Department of Histology and Embryology, Chongqing Medical University, Chongqing, China.,Laboratory of Stem Cells and Tissue Engineering, Chongqing Medical University, Chongqing, China
| | - Qian Xiao
- Department of Histology and Embryology, Chongqing Medical University, Chongqing, China.,Laboratory of Stem Cells and Tissue Engineering, Chongqing Medical University, Chongqing, China
| | - Lin-Mu Chen
- Department of Histology and Embryology, Chongqing Medical University, Chongqing, China.,Laboratory of Stem Cells and Tissue Engineering, Chongqing Medical University, Chongqing, China
| | - Yong Tang
- Department of Histology and Embryology, Chongqing Medical University, Chongqing, China.,Laboratory of Stem Cells and Tissue Engineering, Chongqing Medical University, Chongqing, China
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12
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Sun J, Zhou H, Bai F, Zhang Z, Ren Q. Remyelination: A Potential Therapeutic Strategy for Alzheimer's Disease? J Alzheimers Dis 2018; 58:597-612. [PMID: 28453483 DOI: 10.3233/jad-170036] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Myelin is a lipid-rich multilamellar membrane that wraps around long segments of neuronal axons and it increases the conduction of action potentials, transports the necessary trophic support to the neuronal axons, and reduces the energy consumed by the neuronal axons. Together with axons, myelin is a prerequisite for the higher functions of the central nervous system and complex forms of network integration. Myelin impairments have been suggested to lead to neuronal dysfunction and cognitive decline. Accumulating evidence, including brain imaging and postmortem and genetic association studies, has implicated myelin impairments in Alzheimer's disease (AD). Increasing data link myelin impairments with amyloid-β (Aβ) plaques and tau hyperphosphorylation, which are both present in patients with AD. Moreover, aging and apolipoprotein E (ApoE) may be involved in the myelin impairments observed in patients with AD. Decreased neuronal activity, increased Aβ levels, and inflammation further damage myelin in patients with AD. Furthermore, treatments that promote myelination contribute to the recovery of neuronal function and improve cognition. Therefore, strategies targeting myelin impairment may provide therapeutic opportunities for patients with AD.
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13
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Gu L, Wu D, Tang X, Qi X, Li X, Bai F, Chen X, Ren Q, Zhang Z. Myelin changes at the early stage of 5XFAD mice. Brain Res Bull 2017; 137:285-293. [PMID: 29288735 DOI: 10.1016/j.brainresbull.2017.12.013] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 12/08/2017] [Accepted: 12/26/2017] [Indexed: 02/08/2023]
Abstract
Previous studies have demonstrated myelin deficits in Alzheimer's disease (AD). However, it is still unclear whether myelin deficits occur at early stage of AD. Our study aimed to investigate myelin deficits in 5XFAD mice dynamically in different cognition-associated brain regions at early stage of AD. Transmission electron microscopy (TEM) was applied to detect myelin changes in late-myelinating regions such as prelimbic area (PrL), retrosplenial granular cortex (Rsg), field CA1 of hippocampus (CA1) and entorhinal cortex (ERC) respectively at different stages (1, 2, 3 and 5 months of age) in 5XFAD mouse model. In addition, we assessed spatial learning and memory with Morris water maze (MWM) in 5XFAD mice. Myelin deficits in 5XFAD mice started from 1 month of age and this deterioration continued during ageing, whereas the same myelin abnormality could only be observed in 5-month-old wild-type mice. Additionally, the g-ratio (an index associated with myelin thickness) was increased in 1-month-old 5XFAD mice in the regions including PrL, CA1 and ERC, compared to wild-type mice. As animals aged, the increased g-ratio in 5XFAD appeared in more regions of the brain. Moreover, 5XFAD mice showed spatial memory deficits from 1 month of age and spatial learning deficits from 2 months of age. In conclusion, myelin deficits occurred at an early stage and progressed with ageing in 5XFAD mouse model. Notably, a sequential myelin change was detected in cognition-associated brain regions. Combined with cognitive examinations, this study suggests that myelin changes might contribute to cognitive dysfunction.
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Affiliation(s)
- Lihua Gu
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu, China
| | - Di Wu
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu, China
| | - Xiang Tang
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu, China
| | - Xinyang Qi
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu, China
| | - Xiaoli Li
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu, China
| | - Feng Bai
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu, China
| | - Xiaochun Chen
- Department of Neurology, Fujian Institute of Geriatrics, the Affiliated Union Hospital of Fujian Medical University, Fuzhou, Fujian, China
| | - Qingguo Ren
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu, China.
| | - Zhijun Zhang
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu, China.
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14
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Age-dependent differences in myelin basic protein expression in the hippocampus of young, adult and aged gerbils. Lab Anim Res 2017; 33:237-243. [PMID: 29046699 PMCID: PMC5645602 DOI: 10.5625/lar.2017.33.3.237] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 08/30/2017] [Accepted: 09/01/2017] [Indexed: 11/21/2022] Open
Abstract
Myelin degeneration is one of the characteristics of aging and degenerative diseases. This study investigated age-related alterations in expression of myelin basic protein (MBP) in the hippocampal subregions (dentate gyrus, CA2/3 and CA1 areas) of gerbils of various ages; young (1 month), adult (6 months) and aged (24 months), using western blot and immunohistochemistry. Western blot results showed tendencies of age-related reductions of MBP levels. MBP immunoreactivity was significantly decreased with age in synaptic sites of trisynaptic loops, perforant paths, mossy fibers, and Schaffer collaterals. In particular, MBP immunoreactive fibers in the dentate molecular cell layer (perforant path) was significantly reduced in adult and aged subjects. In addition, MBP immunoreactive mossy fibers in the dentate polymorphic layer and in the CA3 striatum radiatum was significantly decreased in the aged group. Furthermore, we observed similar age-related alterations in the CA1 stratum radiatum (Schaffer collaterals). However, the density of MBP immunoreactive fibers in the dentate granular cell layer and CA stratum pyramidale was decreased with aging. These findings indicate that expression of MBP is age-dependent and tissue specific according to hippocampal layers.
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15
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O'Callaghan J, Holmes H, Powell N, Wells JA, Ismail O, Harrison IF, Siow B, Johnson R, Ahmed Z, Fisher A, Meftah S, O'Neill MJ, Murray TK, Collins EC, Shmueli K, Lythgoe MF. Tissue magnetic susceptibility mapping as a marker of tau pathology in Alzheimer's disease. Neuroimage 2017; 159:334-345. [PMID: 28797738 PMCID: PMC5678288 DOI: 10.1016/j.neuroimage.2017.08.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 07/27/2017] [Accepted: 08/01/2017] [Indexed: 01/15/2023] Open
Abstract
Alzheimer's disease is connected to a number of other neurodegenerative conditions, known collectively as 'tauopathies', by the presence of aggregated tau protein in the brain. Neuroinflammation and oxidative stress in AD are associated with tau pathology and both the breakdown of axonal sheaths in white matter tracts and excess iron accumulation grey matter brain regions. Despite the identification of myelin and iron concentration as major sources of contrast in quantitative susceptibility maps of the brain, the sensitivity of this technique to tau pathology has yet to be explored. In this study, we perform Quantitative Susceptibility Mapping (QSM) and T2* mapping in the rTg4510, a mouse model of tauopathy, both in vivo and ex vivo. Significant correlations were observed between histological measures of myelin content and both mean regional magnetic susceptibility and T2* values. These results suggest that magnetic susceptibility is sensitive to tissue myelin concentrations across different regions of the brain. Differences in magnetic susceptibility were detected in the corpus callosum, striatum, hippocampus and thalamus of the rTg4510 mice relative to wild type controls. The concentration of neurofibrillary tangles was found to be low to intermediate in these brain regions indicating that QSM may be a useful biomarker for early stage detection of tau pathology in neurodegenerative diseases.
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Affiliation(s)
- J O'Callaghan
- UCL Centre for Advanced Biomedical Imaging, Division of Medicine, UCL, UK.
| | - H Holmes
- UCL Centre for Advanced Biomedical Imaging, Division of Medicine, UCL, UK
| | - N Powell
- UCL Centre for Advanced Biomedical Imaging, Division of Medicine, UCL, UK
| | - J A Wells
- UCL Centre for Advanced Biomedical Imaging, Division of Medicine, UCL, UK
| | - O Ismail
- UCL Centre for Advanced Biomedical Imaging, Division of Medicine, UCL, UK
| | - I F Harrison
- UCL Centre for Advanced Biomedical Imaging, Division of Medicine, UCL, UK
| | - B Siow
- UCL Centre for Advanced Biomedical Imaging, Division of Medicine, UCL, UK
| | - R Johnson
- Eli Lilly and Company, 355 E Merrill Street, Dock 48, Indianapolis, IN, 46225, USA
| | - Z Ahmed
- Eli Lilly & Co. Ltd, Erl Wood Manor, Windlesham, Surrey, GU20 6PH, UK
| | - A Fisher
- Eli Lilly & Co. Ltd, Erl Wood Manor, Windlesham, Surrey, GU20 6PH, UK
| | - S Meftah
- Eli Lilly & Co. Ltd, Erl Wood Manor, Windlesham, Surrey, GU20 6PH, UK
| | - M J O'Neill
- Eli Lilly & Co. Ltd, Erl Wood Manor, Windlesham, Surrey, GU20 6PH, UK
| | - T K Murray
- Eli Lilly & Co. Ltd, Erl Wood Manor, Windlesham, Surrey, GU20 6PH, UK
| | - E C Collins
- Eli Lilly and Company, 355 E Merrill Street, Dock 48, Indianapolis, IN, 46225, USA
| | - K Shmueli
- Department of Medical Physics and Biomedical Engineering, UCL, UK
| | - M F Lythgoe
- UCL Centre for Advanced Biomedical Imaging, Division of Medicine, UCL, UK
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16
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Tong M, Leão R, Vimbela GV, Yalcin EB, Kay J, Krotow A, de la Monte SM. Altered temporal lobe white matter lipid ion profiles in an experimental model of sporadic Alzheimer's disease. Mol Cell Neurosci 2017; 82:23-34. [PMID: 28438696 DOI: 10.1016/j.mcn.2017.04.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 02/19/2017] [Accepted: 04/20/2017] [Indexed: 10/19/2022] Open
Abstract
BACKGROUND White matter is an early and important yet under-evaluated target of Alzheimer's disease (AD). Metabolic impairments due to insulin and insulin-like growth factor resistance contribute to white matter degeneration because corresponding signal transduction pathways maintain oligodendrocyte function and survival. METHODS This study utilized a model of sporadic AD in which adult Long Evans rats administered intracerebral streptozotocin (i.c. STZ) developed AD-type neurodegeneration. Temporal lobe white matter lipid ion profiles were characterized by matrix-assisted laser desorption/ionization-imaging mass spectrometry (MALDI-IMS). RESULTS Although the lipid ion species expressed in the i.c. STZ and control groups were virtually identical, i.c. STZ mainly altered the abundances of various lipid ions. Correspondingly, the i.c. STZ group was distinguished from control by principal component analysis and data bar plots. i.c. STZ mainly reduced expression of lipid ions with low m/z's (less than 810) as well as the upper range m/z lipids (m/z 964-986), and increased expression of lipid ions with m/z's between 888 and 937. Phospholipids were mainly included among the clusters inhibited by i.c. STZ, while both sulfatides and phospholipids were increased by i.c. STZ. However, Chi-Square analysis demonstrated significant i.c. STZ-induced trend reductions in phospholipids and increases in sulfatides (P<0.00001). CONCLUSIONS The i.c. STZ model of sporadic AD is associated with broad and sustained abnormalities in temporal lobe white matter lipids. The findings suggest that the i.c. STZ model could be used for pre-clinical studies to assess therapeutic measures for their ability to restore white matter integrity in AD.
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Affiliation(s)
- Ming Tong
- Liver Research Center, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, RI, United States; Division of Gastroenterology, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, RI, United States; Department of Medicine, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, RI, United States
| | - Raiane Leão
- Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Gina V Vimbela
- Department of Chemical Engineering, California State University, Long Beach, CA, United States
| | - Emine B Yalcin
- Liver Research Center, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, RI, United States
| | - Jared Kay
- Liver Research Center, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, RI, United States
| | | | - Suzanne M de la Monte
- Liver Research Center, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, RI, United States; Division of Gastroenterology, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, RI, United States; Division of Neuropathology, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, RI, United States; Department of Medicine, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, RI, United States; Department of Pathology, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, RI, United States; Department of Neurology, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, RI, United States; Department of Neurosurgery, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, RI, United States.
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17
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Koga S, Parks A, Uitti RJ, van Gerpen JA, Cheshire WP, Wszolek ZK, Dickson DW. Profile of cognitive impairment and underlying pathology in multiple system atrophy. Mov Disord 2016; 32:405-413. [PMID: 27859650 DOI: 10.1002/mds.26874] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 10/17/2016] [Accepted: 10/19/2016] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND The objectives of this study were to elucidate any potential association between α-synuclein pathology and cognitive impairment and to determine the profile of cognitive impairment in multiple system atrophy (MSA) patients. To do this, we analyzed the clinical and pathologic features in autopsy-confirmed MSA patients. METHODS We retrospectively reviewed medical records, including neuropsychological test data, in 102 patients with autopsy-confirmed MSA in the Mayo Clinic brain bank. The burden of glial cytoplasmic inclusions and neuronal cytoplasmic inclusions were semiquantitatively scored in the limbic regions and middle frontal gyrus. We also assessed concurrent pathologies potentially causing dementia including Alzheimer's disease, hippocampal sclerosis, and cerebrovascular pathology. RESULTS Of 102 patients, 33 (32%) were documented to have cognitive impairment. Those that received objective testing, deficits primarily in processing speed and attention/executive functions were identified, which suggests a frontal-subcortical pattern of dysfunction. Of these 33 patients with cognitive impairment, 8 patients had concurrent pathologies of dementia. MSA patients with cognitive impairment had a greater burden of neuronal cytoplasmic inclusions in the dentate gyrus than patients without cognitive impairment, both including and excluding patients with concurrent pathologies of dementia. CONCLUSIONS The cognitive deficits observed in this study were more evident on neuropsychological assessment than with cognitive screens. Based on these findings, we recommend that clinicians consider more in-depth neuropsychological assessments if patients with MSA present with cognitive complaints. Although we did not identify the correlation between cognitive deficits and responsible neuroanatomical regions, a greater burden of neuronal cytoplasmic inclusions in the limbic regions was associated with cognitive impairment in MSA. © 2016 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Shunsuke Koga
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA
| | - Adam Parks
- Department of Psychiatry and Psychology, Mayo Clinic, Jacksonville, Florida, USA
| | - Ryan J Uitti
- Department of Neurology, Mayo Clinic, Jacksonville, Florida, USA
| | - Jay A van Gerpen
- Department of Neurology, Mayo Clinic, Jacksonville, Florida, USA
| | | | | | - Dennis W Dickson
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA
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18
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Adenosine A1-Receptors Modulate mTOR Signaling to Regulate White Matter Inflammatory Lesions Induced by Chronic Cerebral Hypoperfusion. Neurochem Res 2016; 41:3272-3277. [PMID: 27662851 DOI: 10.1007/s11064-016-2056-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 07/12/2016] [Accepted: 09/01/2016] [Indexed: 12/20/2022]
Abstract
We sought to investigate the role of the adenosine A1 receptors (A1ARs) in white matter lesions under chronic cerebral hypoperfusion (CCH) and explore the potential repair mechanisms by activation of the receptors. A right unilateral common carotid artery occlusion (rUCCAO) method was used to construct a CCH model. 2-chloro-N6-cyclopentyladenosine (CCPA), a specific agonist of A1ARs, was used to explore the biological mechanisms of repair in white matter lesions under CCH. The expression of mammalian target of rapamycin (mTOR), phosphorylation of mTOR (P-mTOR), myelin basic protein (MBP, a marker of white matter myelination) were detected by Western-blot. Pro-inflammatory cytokine tumor necrosis factor-α (TNF-α) and anti-inflammatory cytokine interleukin-10 (IL-10) levels were determined by ELISA. Compared with the control groups on week 2, 4 and 6, in CCPA-treated groups, the ratio of P-mTOR/mTOR, expression of MBP and IL-10 increased markedly, while the expression of TNF-α reduced at week 6. In conclusion, A1ARs appears to reduce inflammation in white matter via the mTOR signaling pathway in the rUCCAO mice. Therefore, A1ARs may serve as a therapeutic target during the repair of white matter lesions under CCH.
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19
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Nunez K, Kay J, Krotow A, Tong M, Agarwal AR, Cadenas E, de la Monte SM. Cigarette Smoke-Induced Alterations in Frontal White Matter Lipid Profiles Demonstrated by MALDI-Imaging Mass Spectrometry: Relevance to Alzheimer's Disease. J Alzheimers Dis 2016; 51:151-63. [PMID: 26836183 PMCID: PMC5575809 DOI: 10.3233/jad-150916] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
BACKGROUND Meta-analysis has shown that smokers have significantly increased risks for Alzheimer's disease (AD), and neuroimaging studies showed that smoking alters white matter (WM) structural integrity. OBJECTIVE Herein, we characterize the effects of cigarette smoke (CS) exposures and withdrawal on WM myelin lipid composition using matrix assisted laser desorption and ionization-imaging mass spectrometry (MALDI-IMS). METHODS Young adult male A/J mice were exposed to air (8 weeks; A8), CS (4 or 8 weeks; CS4, CS8), or CS8 followed by 2 weeks recovery (CS8 + R). Frontal lobe WM was examined for indices of lipid and protein oxidation and lipid profile alterations by MALDI-IMS. Lipid ions were identified by MS/MS with the LIPID MAPS prediction tools database. Inter-group comparisons were made using principal component analysis and R-generated heatmap. RESULTS CS increased lipid and protein adducts such that higher levels were present in CS8 compared with CS4 samples. CS8 + R reversed CS8 effects and normalized the levels of oxidative stress. MALDI-IMS demonstrated striking CS-associated alterations in WM lipid profiles characterized by either reductions or increases in phospholipids (phosphatidylinositol, phosphatidylserine, phosphatidylcholine, or phosphatidylethanolamine) and sphingolipids (sulfatides), and partial reversal of CS's inhibitory effects with recovery. The heatmap hierarchical dendrogram and PCA distinguished CS exposure, duration, and withdrawal effects on WM lipid profiles. CONCLUSION CS-mediated WM degeneration is associated with lipid peroxidation, protein oxidative injury, and alterations in myelin lipid composition, including shifts in phospholipids and sphingolipids needed for membrane integrity, plasticity, and intracellular signaling. Future goals are to delineate WM abnormalities in AD using MALDI-IMS, and couple the findings with MRI-mass spectroscopy to improve in vivo diagnostics and early detection of brain biochemical responses to treatment.
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Affiliation(s)
- Kavin Nunez
- Liver Research Center, Rhode Island Hospital and the Warren Alpert Medical School of Brown University, Providence, RI, USA
- Molecular Pharmacology, Physiology, and Biotechnology, Providence, RI, USA
| | - Jared Kay
- Liver Research Center, Rhode Island Hospital and the Warren Alpert Medical School of Brown University, Providence, RI, USA
- Departments of Medicine, Rhode Island Hospital and the Warren Alpert Medical School of Brown University, Providence, RI, USA
| | - Alexander Krotow
- Liver Research Center, Rhode Island Hospital and the Warren Alpert Medical School of Brown University, Providence, RI, USA
- Pathobiology Graduate Programs at Brown University, Providence, RI, USA
| | - Ming Tong
- Liver Research Center, Rhode Island Hospital and the Warren Alpert Medical School of Brown University, Providence, RI, USA
- Departments of Medicine, Rhode Island Hospital and the Warren Alpert Medical School of Brown University, Providence, RI, USA
| | - Amit R. Agarwal
- The Department of Pharmacology Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, USA
| | - Enrique Cadenas
- The Department of Pharmacology Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, USA
| | - Suzanne M. de la Monte
- Liver Research Center, Rhode Island Hospital and the Warren Alpert Medical School of Brown University, Providence, RI, USA
- Divisions of Gastroenterology, Rhode Island Hospital and the Warren Alpert Medical School of Brown University, Providence, RI, USA
- Divisions of Neuropathology, Rhode Island Hospital and the Warren Alpert Medical School of Brown University, Providence, RI, USA
- Departments of Medicine, Rhode Island Hospital and the Warren Alpert Medical School of Brown University, Providence, RI, USA
- Departments of Pathology, Rhode Island Hospital and the Warren Alpert Medical School of Brown University, Providence, RI, USA
- Departments of Neurology, Rhode Island Hospital and the Warren Alpert Medical School of Brown University, Providence, RI, USA
- Departments of Neurosurgery, Rhode Island Hospital and the Warren Alpert Medical School of Brown University, Providence, RI, USA
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20
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Yu R, Deochand C, Krotow A, Leão R, Tong M, Agarwal AR, Cadenas E, de la Monte SM. Tobacco Smoke-Induced Brain White Matter Myelin Dysfunction: Potential Co-Factor Role of Smoking in Neurodegeneration. J Alzheimers Dis 2016; 50:133-48. [PMID: 26639972 PMCID: PMC5577392 DOI: 10.3233/jad-150751] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND Meta-analysis studies showed that smokers have increased risk for developing Alzheimer's disease (AD) compared with non-smokers, and neuroimaging studies revealed that smoking damages white matter structural integrity. OBJECTIVE The present study characterizes the effects of side-stream (second hand) cigarette smoke (CS) exposures on the expression of genes that regulate oligodendrocyte myelin-synthesis, maturation, and maintenance and neuroglial functions. METHODS Adult male A/J mice were exposed to air (8 weeks; A8), CS (4 or 8 weeks; CS4, CS8), or CS8 followed by 2 weeks recovery (CS8 + R). The frontal lobes were used for histology and qRT-PCR analysis. RESULTS Luxol fast blue, Hematoxylin and Eosin stained histological sections revealed CS-associated reductions in myelin staining intensity and narrowing of the corpus callosum. CS exposures broadly decreased mRNA levels of immature and mature oligodendrocyte myelin-associated, neuroglial, and oligodendrocyte-related transcription factors. These effects were more prominent in the CS8 compared with CS4 group, suggesting that molecular abnormalities linked to white matter atrophy and myelin loss worsen with duration of CS exposure. Recovery normalized or upregulated less than 25% of the suppressed genes; in most cases, inhibition of gene expression was either sustained or exacerbated. CONCLUSION CS exposures broadly inhibit expression of genes needed for myelin synthesis and maintenance. These adverse effects often were not reversed by short-term CS withdrawal. The results support the hypothesis that smoking contributes to white matter degeneration, and therefore could be a key risk factor for a number of neurodegenerative diseases, including AD.
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Affiliation(s)
- Rosa Yu
- Liver Research Center, Divisions of Rhode Island Hospital and the Warren Alpert Medical School of Brown University, Providence, RI, USA
- Gastroenterology and Rhode Island Hospital and the Warren Alpert Medical School of Brown University, Providence, RI, USA
- Medicine, Rhode Island Hospital and the Warren Alpert Medical School of Brown University, Providence, RI, USA
| | - Chetram Deochand
- Liver Research Center, Divisions of Rhode Island Hospital and the Warren Alpert Medical School of Brown University, Providence, RI, USA
- Gastroenterology and Rhode Island Hospital and the Warren Alpert Medical School of Brown University, Providence, RI, USA
- Medicine, Rhode Island Hospital and the Warren Alpert Medical School of Brown University, Providence, RI, USA
- Molecular Pharmacology and Physiology Graduate Program at Brown University, Providence, RI, USA
| | - Alexander Krotow
- Molecular Pharmacology and Physiology Graduate Program at Brown University, Providence, RI, USA
| | - Raiane Leão
- Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Ming Tong
- Liver Research Center, Divisions of Rhode Island Hospital and the Warren Alpert Medical School of Brown University, Providence, RI, USA
- Gastroenterology and Rhode Island Hospital and the Warren Alpert Medical School of Brown University, Providence, RI, USA
- Medicine, Rhode Island Hospital and the Warren Alpert Medical School of Brown University, Providence, RI, USA
| | - Amit R. Agarwal
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, USA
| | - Enrique Cadenas
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, USA
| | - Suzanne M. de la Monte
- Liver Research Center, Divisions of Rhode Island Hospital and the Warren Alpert Medical School of Brown University, Providence, RI, USA
- Gastroenterology and Rhode Island Hospital and the Warren Alpert Medical School of Brown University, Providence, RI, USA
- Neuropathology, and Departments of Rhode Island Hospital and the Warren Alpert Medical School of Brown University, Providence, RI, USA
- Medicine, Rhode Island Hospital and the Warren Alpert Medical School of Brown University, Providence, RI, USA
- Pathology, Rhode Island Hospital and the Warren Alpert Medical School of Brown University, Providence, RI, USA
- Neurology, Rhode Island Hospital and the Warren Alpert Medical School of Brown University, Providence, RI, USA
- Neurosurgery, Rhode Island Hospital and the Warren Alpert Medical School of Brown University, Providence, RI, USA
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21
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Zhan X, Jickling GC, Ander BP, Stamova B, Liu D, Kao PF, Zelin MA, Jin LW, DeCarli C, Sharp FR. Myelin basic protein associates with AβPP, Aβ1-42, and amyloid plaques in cortex of Alzheimer's disease brain. J Alzheimers Dis 2015; 44:1213-29. [PMID: 25697841 DOI: 10.3233/jad-142013] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The goal of this study was to show that myelin and axons in cortical gray matter are damaged in Alzheimer's disease (AD) brain. Superior temporal gyrus gray matter of AD patients (9 male, 14 female) was compared to cognitively normal controls (8 male, 7 female). Myelin basic protein (MBP) and a degraded myelin basic protein complex (dMBP) were quantified by Western blot. Brain sections were immunostained for MBP, dMBP, axonal neurofilament protein (NF), autophagy marker microtubule-associated proteins 1A/B light chain 3B precursor (LC3B), amyloid-β protein precursor (AβPP), and amyloid markers amyloid β1-42 (Aβ1-42) and FSB. Co-immunoprecipitation and mass spectroscopy evaluated interaction of AβPP/Aβ1-42 with MBP/dMBP. Evidence of axonal injury in AD cortex included appearance of AβPP in NF stained axons, and NF at margins of amyloid plaques. Evidence of myelin injury in AD cortex included (1) increased dMBP in AD gray matter compared to control (p < 0.001); (2) dMBP in AD neurons; and (3) increased LC3B that co-localized with MBP. Evidence of interaction of AβPP/Aβ1-42 with myelin or axonal components included (1) greater binding of dMBP with AβPP in AD brain; (2) MBP at the margins of amyloid plaques; (3) dMBP co-localized with Aβ1-42 in the core of amyloid plaques in AD brains; and (4) interactions between Aβ1-42 and MBP/dMBP by co-immunoprecipitation and mass spectrometry. We conclude that damaged axons may be a source of AβPP. dMBP, MBP, and NF associate with amyloid plaques and dMBP associates with AβPP and Aβ1-42. These molecules could be involved in formation of amyloid plaques.
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Affiliation(s)
- Xinhua Zhan
- Department of Neurology, MIND Institute, University of California at Davis, Sacramento, CA, USA
| | - Glen C Jickling
- Department of Neurology, MIND Institute, University of California at Davis, Sacramento, CA, USA
| | - Bradley P Ander
- Department of Neurology, MIND Institute, University of California at Davis, Sacramento, CA, USA
| | - Boryana Stamova
- Department of Neurology, MIND Institute, University of California at Davis, Sacramento, CA, USA
| | - DaZhi Liu
- Department of Neurology, MIND Institute, University of California at Davis, Sacramento, CA, USA
| | - Patricia F Kao
- Alzheimer's Disease Center, University of California at Davis, Sacramento, CA, USA Department of Pathology, University of California at Davis, Sacramento, CA, USA
| | - Mariko A Zelin
- Alzheimer's Disease Center, University of California at Davis, Sacramento, CA, USA Department of Pathology, University of California at Davis, Sacramento, CA, USA
| | - Lee-Way Jin
- Alzheimer's Disease Center, University of California at Davis, Sacramento, CA, USA Department of Pathology, University of California at Davis, Sacramento, CA, USA
| | - Charles DeCarli
- Department of Neurology, MIND Institute, University of California at Davis, Sacramento, CA, USA Alzheimer's Disease Center, University of California at Davis, Sacramento, CA, USA
| | - Frank R Sharp
- Department of Neurology, MIND Institute, University of California at Davis, Sacramento, CA, USA
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22
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Kennedy BC, Dimova JG, Siddappa AJM, Tran PV, Gewirtz JC, Georgieff MK. Prenatal choline supplementation ameliorates the long-term neurobehavioral effects of fetal-neonatal iron deficiency in rats. J Nutr 2014; 144:1858-65. [PMID: 25332485 PMCID: PMC4195423 DOI: 10.3945/jn.114.198739] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 07/12/2014] [Accepted: 08/21/2014] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Gestational iron deficiency in humans and rodents produces long-term deficits in cognitive and socioemotional function and alters expression of plasticity genes in the hippocampus that persist despite iron treatment. Prenatal choline supplementation improves cognitive function in other rodent models of developmental insults. OBJECTIVE The objective of this study was to determine whether prenatal choline supplementation prevents the long-term effects of fetal-neonatal iron deficiency on cognitive and social behaviors and hippocampal gene expression. METHODS Pregnant rat dams were administered an iron-deficient (2-6 g/kg iron) or iron-sufficient (IS) (200 g/kg iron) diet from embryonic day (E) 3 to postnatal day (P) 7 with or without choline supplementation (5 g/kg choline chloride, E11-18). Novel object recognition (NOR) in the test vs. acquisition phase, social approach (SA), and hippocampal mRNA expression were compared at P65 in 4 male adult offspring groups: formerly iron deficient (FID), FID with choline supplementation (FID-C), IS, and IS with choline supplementation. RESULTS Relative to the intact NOR in IS rats (acquisition: 47.9%, test: 60.2%, P < 0.005), FID adult rats had impaired recognition memory at the 6-h delay (acquisition: 51.4%, test: 55.1%, NS), accompanied by a 15% reduction in hippocampal expression of brain-derived neurotrophic factor (Bdnf) (P < 0.05) and myelin basic protein (Mbp) (P < 0.05). Prenatal choline supplementation in FID rats restored NOR (acquisition: 48.8%, test: 64.4%, P < 0.0005) and increased hippocampal gene expression (FID-C vs. FID group: Bdnf, Mbp, P < 0.01). SA was also reduced in FID rats (P < 0.05 vs. IS rats) but was only marginally improved by prenatal choline supplementation. CONCLUSIONS Deficits in recognition memory, but not social behavior, resulting from gestational iron deficiency are attenuated by prenatal choline supplementation, potentially through preservation of hippocampal Bdnf and Mbp expression. Prenatal choline supplementation may be a promising adjunct treatment for fetal-neonatal iron deficiency.
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Affiliation(s)
- Bruce C Kennedy
- Graduate Program in Neuroscience, Center for Neurobehavioral Development,
| | | | - Asha J M Siddappa
- Center for Neurobehavioral Development, Department of Pediatrics, and
| | - Phu V Tran
- Center for Neurobehavioral Development, Department of Pediatrics, and
| | - Jonathan C Gewirtz
- Graduate Program in Neuroscience, Center for Neurobehavioral Development, Department of Psychology
| | - Michael K Georgieff
- Graduate Program in Neuroscience, Center for Neurobehavioral Development, Department of Pediatrics, and Institute of Child Development, University of Minnesota, Minneapolis, MN
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23
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Agosta F, Dalla Libera D, Spinelli EG, Finardi A, Canu E, Bergami A, Bocchio Chiavetto L, Baronio M, Comi G, Martino G, Matteoli M, Magnani G, Verderio C, Furlan R. Myeloid microvesicles in cerebrospinal fluid are associated with myelin damage and neuronal loss in mild cognitive impairment and Alzheimer disease. Ann Neurol 2014; 76:813-25. [DOI: 10.1002/ana.24235] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Revised: 07/25/2014] [Accepted: 07/25/2014] [Indexed: 12/11/2022]
Affiliation(s)
- Federica Agosta
- Division of Neuroscience, Institute of Experimental Neurology; Scientific Institute San Raffaele; Milan
| | - Dacia Dalla Libera
- Division of Neuroscience, Institute of Experimental Neurology; Scientific Institute San Raffaele; Milan
| | - Edoardo Gioele Spinelli
- Division of Neuroscience, Institute of Experimental Neurology; Scientific Institute San Raffaele; Milan
| | - Annamaria Finardi
- Division of Neuroscience, Institute of Experimental Neurology; Scientific Institute San Raffaele; Milan
| | - Elisa Canu
- Division of Neuroscience, Institute of Experimental Neurology; Scientific Institute San Raffaele; Milan
| | - Alessandra Bergami
- Division of Neuroscience, Institute of Experimental Neurology; Scientific Institute San Raffaele; Milan
| | | | | | - Giancarlo Comi
- Division of Neuroscience, Institute of Experimental Neurology; Scientific Institute San Raffaele; Milan
- Vita-Salute San Raffaele University; Milan
| | - Gianvito Martino
- Division of Neuroscience, Institute of Experimental Neurology; Scientific Institute San Raffaele; Milan
| | - Michela Matteoli
- CNR Institute of Neuroscience and Department of Medical Pharmacology; Milan
- Istituto Clinico Humanitas IRCCS; Milan Italy
| | - Giuseppe Magnani
- Division of Neuroscience, Institute of Experimental Neurology; Scientific Institute San Raffaele; Milan
| | - Claudia Verderio
- CNR Institute of Neuroscience and Department of Medical Pharmacology; Milan
- Istituto Clinico Humanitas IRCCS; Milan Italy
| | - Roberto Furlan
- Division of Neuroscience, Institute of Experimental Neurology; Scientific Institute San Raffaele; Milan
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24
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Searcy JL, Le Bihan T, Salvadores N, McCulloch J, Horsburgh K. Impact of age on the cerebrovascular proteomes of wild-type and Tg-SwDI mice. PLoS One 2014; 9:e89970. [PMID: 24587158 PMCID: PMC3935958 DOI: 10.1371/journal.pone.0089970] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Accepted: 01/23/2014] [Indexed: 12/13/2022] Open
Abstract
The structural integrity of cerebral vessels is compromised during ageing. Abnormal amyloid (Aβ) deposition in the vasculature can accelerate age-related pathologies. The cerebrovascular response associated with ageing and microvascular Aβ deposition was defined using quantitative label-free shotgun proteomic analysis. Over 650 proteins were quantified in vessel-enriched fractions from the brains of 3 and 9 month-old wild-type (WT) and Tg-SwDI mice. Sixty-five proteins were significantly increased in older WT animals and included several basement membrane proteins (nidogen-1, basement membrane-specific heparan sulfate proteoglycan core protein, laminin subunit gamma-1 precursor and collagen alpha-2(IV) chain preproprotein). Twenty-four proteins were increased and twenty-one decreased in older Tg-SwDI mice. Of these, increases in Apolipoprotein E (APOE) and high temperature requirement serine protease-1 (HTRA1) and decreases in spliceosome and RNA-binding proteins were the most prominent. Only six shared proteins were altered in both 9-month old WT and Tg-SwDI animals. The age-related proteomic response in the cerebrovasculature was distinctly different in the presence of microvascular Aβ deposition. Proteins found differentially expressed within the WT and Tg-SwDI animals give greater insight to the mechanisms behind age-related cerebrovascular dysfunction and pathologies and may provide novel therapeutic targets.
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Affiliation(s)
- James L Searcy
- Centre for Neuroregeneration, University of Edinburgh, Edinburgh, United Kingdom
| | - Thierry Le Bihan
- SynthSys - Synthetic & Systems Biology, University of Edinburgh, Edinburgh, United Kingdom ; Institute of Structural and Molecular Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Natalia Salvadores
- Centre for Neuroregeneration, University of Edinburgh, Edinburgh, United Kingdom
| | - James McCulloch
- Centre for Cognitive and Neural Systems, University of Edinburgh, Edinburgh, United Kingdom ; Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, United Kingdom
| | - Karen Horsburgh
- Centre for Neuroregeneration, University of Edinburgh, Edinburgh, United Kingdom ; Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, United Kingdom
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25
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Powell D, Caban-Holt A, Jicha G, Robertson W, Davis R, Gold BT, Schmitt FA, Head E. Frontal white matter integrity in adults with Down syndrome with and without dementia. Neurobiol Aging 2014; 35:1562-9. [PMID: 24582640 DOI: 10.1016/j.neurobiolaging.2014.01.137] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 01/16/2014] [Accepted: 01/27/2014] [Indexed: 10/25/2022]
Abstract
Adults with Down syndrome (DS) are at high risk for developing Alzheimer's disease after the age of 40 years. To detect white matter (WM) changes in the brain linked to dementia, fractional anisotropy (FA) from diffusion tensor imaging was used. We hypothesized that adults with DS without dementia (DS n = 10), DS with dementia (DSAD n = 10) and age matched non-DS subjects (CTL n = 10) would show differential levels of FA and an association with scores from the Brief Praxis Test and the Severe Impairment Battery. WM integrity differences in DS compared with CTL were found predominantly in the frontal lobes. Across all DS adults, poorer Brief Praxis Test performance correlated with reduced FA in the corpus callosum as well as several association tracts, primarily within frontoparietal regions. Our results demonstrate significantly lower WM integrity in DS compared with controls, particularly in the frontal tracts. DS-related WM integrity reductions in a number of tracts were associated with poorer cognition. These preliminary results suggest that late myelinating frontal pathways may be vulnerable to aging in DS.
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Affiliation(s)
- David Powell
- Magnetic Resonance Imaging and Spectroscopy Center, University of Kentucky, Lexington, KY, USA
| | - Allison Caban-Holt
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Gregory Jicha
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA; Department of Neurology, University of Kentucky, Lexington, KY, USA
| | | | - Roberta Davis
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Brian T Gold
- Magnetic Resonance Imaging and Spectroscopy Center, University of Kentucky, Lexington, KY, USA; Department of Anatomy and Neurobiology, University of Kentucky, Lexington, KY, USA
| | - Frederick A Schmitt
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA; Department of Neurology, University of Kentucky, Lexington, KY, USA
| | - Elizabeth Head
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA; Department of Molecular and Biomedical Pharmacology, University of Kentucky, Lexington, KY, USA.
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26
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Rowley J, Fonov V, Wu O, Eskildsen SF, Schoemaker D, Wu L, Mohades S, Shin M, Sziklas V, Cheewakriengkrai L, Shmuel A, Dagher A, Gauthier S, Rosa-Neto P. White matter abnormalities and structural hippocampal disconnections in amnestic mild cognitive impairment and Alzheimer's disease. PLoS One 2013; 8:e74776. [PMID: 24086371 PMCID: PMC3785512 DOI: 10.1371/journal.pone.0074776] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 08/07/2013] [Indexed: 01/18/2023] Open
Abstract
The purpose of this project was to evaluate white matter degeneration and its impact on hippocampal structural connectivity in patients with amnestic mild cognitive impairment, non-amnestic mild cognitive impairment and Alzheimer’s disease. We estimated white matter fractional anisotropy, mean diffusivity and hippocampal structural connectivity in two independent cohorts. The ADNI cohort included 108 subjects [25 cognitively normal, 21 amnestic mild cognitive impairment, 47 non-amnestic mild cognitive impairment and 15 Alzheimer’s disease]. A second cohort included 34 subjects [15 cognitively normal and 19 amnestic mild cognitive impairment] recruited in Montreal. All subjects underwent clinical and neuropsychological assessment in addition to diffusion and T1 MRI. Individual fractional anisotropy and mean diffusivity maps were generated using FSL-DTIfit. In addition, hippocampal structural connectivity maps expressing the probability of connectivity between the hippocampus and cortex were generated using a pipeline based on FSL-probtrackX. Voxel-based group comparison statistics of fractional anisotropy, mean diffusivity and hippocampal structural connectivity were estimated using Tract-Based Spatial Statistics. The proportion of abnormal to total white matter volume was estimated using the total volume of the white matter skeleton. We found that in both cohorts, amnestic mild cognitive impairment patients had 27-29% white matter volume showing higher mean diffusivity but no significant fractional anisotropy abnormalities. No fractional anisotropy or mean diffusivity differences were observed between non-amnestic mild cognitive impairment patients and cognitively normal subjects. Alzheimer’s disease patients had 66.3% of normalized white matter volume with increased mean diffusivity and 54.3% of the white matter had reduced fractional anisotropy. Reduced structural connectivity was found in the hippocampal connections to temporal, inferior parietal, posterior cingulate and frontal regions only in the Alzheimer’s group. The severity of white matter degeneration appears to be higher in advanced clinical stages, supporting the construct that these abnormalities are part of the pathophysiological processes of Alzheimer’s disease.
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Affiliation(s)
- Jared Rowley
- Translational Neuroimaging Laboratory, McGill Centre for Studies in Aging (MCSA), McGill University, Montreal, Quebec, Canada
| | - Vladimir Fonov
- Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Ona Wu
- Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts, United States of America
| | | | - Dorothee Schoemaker
- Translational Neuroimaging Laboratory, McGill Centre for Studies in Aging (MCSA), McGill University, Montreal, Quebec, Canada
| | - Liyong Wu
- Translational Neuroimaging Laboratory, McGill Centre for Studies in Aging (MCSA), McGill University, Montreal, Quebec, Canada
- Department of Neurology, Xuan Wu Hospital, Capital Medical University, Beijing, China
| | - Sara Mohades
- Translational Neuroimaging Laboratory, McGill Centre for Studies in Aging (MCSA), McGill University, Montreal, Quebec, Canada
| | - Monica Shin
- Translational Neuroimaging Laboratory, McGill Centre for Studies in Aging (MCSA), McGill University, Montreal, Quebec, Canada
| | - Viviane Sziklas
- Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Laksanun Cheewakriengkrai
- Translational Neuroimaging Laboratory, McGill Centre for Studies in Aging (MCSA), McGill University, Montreal, Quebec, Canada
| | - Amir Shmuel
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Alain Dagher
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Serge Gauthier
- Translational Neuroimaging Laboratory, McGill Centre for Studies in Aging (MCSA), McGill University, Montreal, Quebec, Canada
| | - Pedro Rosa-Neto
- Translational Neuroimaging Laboratory, McGill Centre for Studies in Aging (MCSA), McGill University, Montreal, Quebec, Canada
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
- * E-mail:
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27
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Papma JM, de Groot M, de Koning I, Mattace-Raso FU, van der Lugt A, Vernooij MW, Niessen WJ, van Swieten JC, Koudstaal PJ, Prins ND, Smits M. Cerebral small vessel disease affects white matter microstructure in mild cognitive impairment. Hum Brain Mapp 2013; 35:2836-51. [PMID: 24115179 DOI: 10.1002/hbm.22370] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Revised: 06/12/2013] [Accepted: 06/24/2013] [Indexed: 11/10/2022] Open
Abstract
Microstructural white matter deterioration is a frequent finding in mild cognitive impairment (MCI), potentially underlying default mode network (DMN) dysfunctioning. Thus far, microstructural damage in MCI has been attributed to Alzheimer's disease pathophysiology. A cerebrovascular role, in particular the role of cerebral small vessel disease (CSVD), received less interest. Here, we used diffusion tensor imaging (DTI) to examine the role of CSVD in microstructural deterioration within the normal appearing white matter (NAWM) in MCI. MCI patients were subdivided into those with (n = 20) and without (n = 31) macrostructural CSVD evidence on MRI. Using TBSS we performed microstructural integrity comparisons within the whole brain NAWM. Secondly, we segmented white matter tracts interconnecting DMN brain regions by means of automated tractography segmentation. We used NAWM DTI measures from these tracts as dependent variables in a stepwise-linear regression analysis, with structural and demographical predictors. Our results indicated microstructural deterioration within the anterior corpus callosum, internal and external capsule and periventricular white matter in MCI patients with CSVD, while in MCI patients without CSVD, deterioration was restricted to the right perforant path, a tract along the hippocampus. Within the full cohort of MCI patients, microstructure within the NAWM of the DMN fiber tracts was affected by the presence of CSVD. Within the cingulum along the hippocampal cortex we found a relationship between microstructural integrity and ipsilateral hippocampal volume and the extent of white matter hyperintensity. In conclusion, we found evidence of CSVD-related microstructural damage in fiber tracts subserving the DMN in MCI.
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Affiliation(s)
- Janne M Papma
- Department of Neurology, Erasmus MC-University Medical Center, Rotterdam, The Netherlands; Department of Radiology, Erasmus MC-University Medical Center, Rotterdam, The Netherlands
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28
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Abstract
Whether mild cognitive impairment (MCI) has a distinct neuropathological profile that reflects an intermediate state between no cognitive impairment and dementia is not clear. Identifying which biological events occur at the earliest stage of progressive disease and which are secondary to the neuropathological process is important for understating pathological pathways and for targeted disease prevention. Many studies have now reported on the neurobiology of this intermediate stage. In this systematic review, we synthesize current evidence on the neuropathological profile of MCI. A total of 162 studies were identified with varied definition of MCI, settings ranging from population to specialist clinics and a wide range of objectives. From these studies, it is clear that MCI is neuropathologically complex and cannot be understood within a single framework. Pathological changes identified include plaque and tangle formation, vascular pathologies, neurochemical deficits, cellular injury, inflammation, oxidative stress, mitochondrial changes, changes in genomic activity, synaptic dysfunction, disturbed protein metabolism and disrupted metabolic homeostasis. Determining which factors primarily drive neurodegeneration and dementia and which are secondary features of disease progression still requires further research. Standardization of the definition of MCI and reporting of pathology would greatly assist in building an integrated picture of the clinical and neuropathological profile of MCI.
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29
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Bennett DA, Schneider JA, Arvanitakis Z, Wilson RS. Overview and findings from the religious orders study. Curr Alzheimer Res 2012; 9:628-45. [PMID: 22471860 PMCID: PMC3409291 DOI: 10.2174/156720512801322573] [Citation(s) in RCA: 508] [Impact Index Per Article: 39.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2011] [Revised: 12/27/2011] [Accepted: 01/12/2012] [Indexed: 12/22/2022]
Abstract
UNLABELLED The Religious Orders Study is a longitudinal clinical-pathologic cohort study of aging and Alzheimer's disease (AD). In this manuscript, we summarize the study methods including the study design and describe the clinical evaluation, assessment of risk factors, collection of ante-mortem biological specimens, brain autopsy and collection of selected postmortem data. THE RESULTS (1) review the relation of neuropathologic indices to clinical diagnoses and cognition proximate to death; (2) examine the relation of risk factors to clinical outcomes; (3) examine the relation of risk factors to measures of neuropathology; and (4) summarize additional study findings. We then discuss and contextualize the study findings.
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Affiliation(s)
- David A Bennett
- Rush Alzheimer's Disease Center, Rush University Medical Center, 600 S. Paulina, Suite 1028, Chicago, IL 60612, USA.
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30
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Xing Y, Samuvel DJ, Stevens SM, Dubno JR, Schulte BA, Lang H. Age-related changes of myelin basic protein in mouse and human auditory nerve. PLoS One 2012; 7:e34500. [PMID: 22496821 PMCID: PMC3320625 DOI: 10.1371/journal.pone.0034500] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Accepted: 03/06/2012] [Indexed: 11/19/2022] Open
Abstract
Age-related hearing loss (presbyacusis) is the most common type of hearing impairment. One of the most consistent pathological changes seen in presbyacusis is the loss of spiral ganglion neurons (SGNs). Defining the cellular and molecular basis of SGN degeneration in the human inner ear is critical to gaining a better understanding of the pathophysiology of presbyacusis. However, information on age-related cellular and molecular alterations in the human spiral ganglion remains scant, owing to the very limited availably of human specimens suitable for high resolution morphological and molecular analysis. This study aimed at defining age-related alterations in the auditory nerve in human temporal bones and determining if immunostaining for myelin basic protein (MBP) can be used as an alternative approach to electron microscopy for evaluating myelin degeneration. For comparative purposes, we evaluated ultrastructural alternations and changes in MBP immunostaining in aging CBA/CaJ mice. We then examined 13 temporal bones from 10 human donors, including 4 adults aged 38-46 years (middle-aged group) and 6 adults aged 63-91 years (older group). Similar to the mouse, intense immunostaining of MBP was present throughout the auditory nerve of the middle-aged human donors. Significant declines in MBP immunoreactivity and losses of MBP(+) auditory nerve fibers were observed in the spiral ganglia of both the older human and aged mouse ears. This study demonstrates that immunostaining for MBP in combination with confocal microscopy provides a sensitive, reliable, and efficient method for assessing alterations of myelin sheaths in the auditory nerve. The results also suggest that myelin degeneration may play a critical role in the SGN loss and the subsequent decline of the auditory nerve function in presbyacusis.
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Affiliation(s)
- Yazhi Xing
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Devadoss J. Samuvel
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Shawn M. Stevens
- Department of Otolaryngology – Head & Neck Surgery, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Judy R. Dubno
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina, United States of America
- Department of Otolaryngology – Head & Neck Surgery, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Bradley A. Schulte
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina, United States of America
- Department of Otolaryngology – Head & Neck Surgery, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Hainan Lang
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina, United States of America
- * E-mail:
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31
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Chiang GC, Zhan W, Schuff N, Weiner MW. White matter alterations in cognitively normal apoE ε2 carriers: insight into Alzheimer resistance? AJNR Am J Neuroradiol 2012; 33:1392-7. [PMID: 22383234 DOI: 10.3174/ajnr.a2984] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE The basis for decreased vulnerability to AD among apoE ε2 carriers is unknown. The purpose of this study was to use diffusion tensor imaging to detect possible differences in white matter integrity between cognitively normal elderly apoE ε2 carriers and apoE ε3/ε3 controls. MATERIALS AND METHODS Thirty-nine cognitively normal elderly individuals (19 heterozygous carriers of the apoE ε2 allele, 20 apoE ε3/ε3 subjects as controls) underwent diffusion tensor MR imaging on a 4T scanner. Fractional anisotropy, MD, and axial and radial diffusivity were compared using a ROI approach. In addition, an exploratory whole-brain analysis of fractional anisotropy between the 2 groups was undertaken using TBSS. RESULTS apoE ε2 carriers had higher FA in the posterior cingulate white matter (P = .01) and anterior corpus callosum (P = .005) than apoE ε3/ε3 controls, secondary to lower radial diffusivity. No significant differences in the FA of the posterior corpus callosum, anterior cingulate white matter, or parahippocampal white matter were seen. Whole-brain TBSS analysis detected regions of higher FA in the apoE ε2 group in the superior longitudinal fasciculus, right thalamus, and the bilateral anterior limbs of the internal capsule, in addition to the posterior cingulum and corpus callosum (P < .005). There were no regions in which the apoE ε3/ε3 group had higher FA. CONCLUSIONS apoE ε2 carriers harbor more robust white matter integrity that may be associated with decreased vulnerability to developing AD. This provides further evidence that regional DTI metrics may serve as early imaging biomarkers of AD risk.
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Affiliation(s)
- G C Chiang
- Center for Imaging of Neurodegenerative Diseases, Department of Veteran Affairs Medical Center, San Francisco, California, USA.
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32
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Abstract
Alzheimer's disease (AD) is a cognitive disorder with a number of complex neuropathologies, including, but not limited to, neurofibrillary tangles, neuritic plaques, neuronal shrinkage, hypomyelination, neuroinflammation and cholinergic dysfunction. The role of underlying pathological processes in the evolution of the cholinergic deficit responsible for cognitive decline has not been elucidated. Furthermore, generation of testable hypotheses for defining points of pharmacological intervention in AD are complicated by the large scale occurrence of older individuals dying with no cognitive impairment despite having a high burden of AD pathology (plaques and tangles). To further complicate these research challenges, there is no animal model that reproduces the combined hallmark neuropathologies of AD. These research limitations have stimulated the application of 'omics' technologies in AD research with the goals of defining biologic markers of disease and disease progression and uncovering potential points of pharmacological intervention for the design of AD therapeutics. In the case of sporadic AD, the dominant form of dementia, genomics has revealed that the ε4 allele of apolipoprotein E, a lipid transport/chaperone protein, is a susceptibility factor. This seminal observation points to the importance of lipid dynamics as an area of investigation in AD. In this regard, lipidomics studies have demonstrated that there are major deficits in brain structural glycerophospholipids and sphingolipids, as well as alterations in metabolites of these complex structural lipids, which act as signaling molecules. Peroxisomal dysfunction appears to be a key component of the changes in glycerophospholipid deficits. In this review, lipid alterations and their potential roles in the pathophysiology of AD are discussed.
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Affiliation(s)
- Paul L Wood
- Metabolomics Unit, Department of Pharmacology, DeBusk College of Osteopathic Medicine, Lincoln Memorial University, 6965 Cumberland Gap Parkway, Harrogate, TN 37752, USA.
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Desai MK, Mastrangelo MA, Ryan DA, Sudol KL, Narrow WC, Bowers WJ. Early oligodendrocyte/myelin pathology in Alzheimer's disease mice constitutes a novel therapeutic target. THE AMERICAN JOURNAL OF PATHOLOGY 2010; 177:1422-35. [PMID: 20696774 DOI: 10.2353/ajpath.2010.100087] [Citation(s) in RCA: 171] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The detection of myelin disruptions in Alzheimer's disease (AD)-affected brain raises the possibility that oligodendrocytes undergo pathophysiological assault over the protracted course of this neurodegenerative disease. Oligodendrocyte compromise arising from direct toxic effects imparted by pathological amyloid-beta peptides and/or through signals derived from degenerating neurons could play an important role in the disease process. We previously demonstrated that 3xTg-AD mice, which harbor the human amyloid precursor protein Swedish mutant transgene, presenilin knock-in mutation, and tau P301L mutant transgene, exhibit significant alterations in overall myelination patterns and oligodendrocyte status at time points preceding the appearance of amyloid and tau pathology. Herein, we demonstrate that Abeta(1-42) leads to increased caspase-3 expression and apoptotic cell death of both nondifferentiated and differentiated mouse oligodendrocyte precursor (mOP) cells in vitro. Through use of a recombinant adeno-associated virus serotype-2 (rAAV2) vector expressing an Abeta(1-42)-specific intracellular antibody (intrabody), oligodendrocyte and myelin marker expression, as well as myelin integrity, were restored in the vector-infused brain regions of 3xTg-AD mice. Overall, this work provides further insights into the impact of Abeta(1-42)-mediated toxicity on the temporal and spatial progression of subtle myelin disruption during the early presymptomatic stages of AD and may help to validate new therapeutic options designed to avert these early impairments.
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Affiliation(s)
- Maya K Desai
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, New York, USA
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Wang R, Wang S, Malter JS, Wang DS. Effects of 4-hydroxy-nonenal and Amyloid-beta on expression and activity of endothelin converting enzyme and insulin degrading enzyme in SH-SY5Y cells. J Alzheimers Dis 2009; 17:489-501. [PMID: 19363254 DOI: 10.3233/jad-2009-1066] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The cerebral accumulation of amyloid-beta (Abeta) is a consistent feature of and likely contributor to the development of Alzheimer's disease (AD). In addition to dysregulated production, increasing experimental evidence suggests reduced catabolism plays an important role in Abeta accumulation. Although endothelin converting enzyme (ECE) and insulin degrading enzyme (IDE) degrade and thus contribute to regulating the steady-state levels of Abeta, how these enzymes are regulated remain poorly understood. In this study, we investigated the effects of 4-hydroxy-nonenal (HNE) and Abeta on the expression and activity of ECE-1 and IDE in human neuroblastoma SH-SY5Y cells. Treatment with HNE or Abeta upregulated ECE-1 mRNA and protein, while IDE was unchanged. Although both ECE-1 and IDE were oxidized within 24 h of HNE or Abeta treatment, ECE-1 catalytic activity was elevated while IDE specific activity was unchanged. The results demonstrated for the first time that both ECE-1 and IDE are substrates of HNE modification induced by Abeta. In addition, the results suggest complex mechanisms underlying the regulation of their enzymatic activity.
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Affiliation(s)
- Rui Wang
- Department of Pathology and Laboratory Medicine, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53706, USA
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Stebbins GT, Murphy CM. Diffusion tensor imaging in Alzheimer's disease and mild cognitive impairment. Behav Neurol 2009; 21:39-49. [PMID: 19847044 PMCID: PMC3010401 DOI: 10.3233/ben-2009-0234] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Structural magnetic resonance imaging (MRI) studies of Alzheimer’s disease and mild cognitive impairment (MCI) have focused on the hippocampus and entorhinal cortex; gray matter structures in the medial temporal lobe. Few studies have investigated the integrity of white matter in patients with AD or MCI. Diffusion tensor imaging (DTI) is a MRI technique that allows for the interrogation of the microstructural integrity of white matter. Based on increases in translational diffusion (mean diffusivity: MD) and decreases directional diffusion (fractional anisotropy: FA) damage to white matter can be assessed. Studies have identified regions of increased MD and decreased FA in patients with AD and MCI in all lobes of the brain, as well as medial temporal lobe structures including the hippocampus, entorhinal cortex and parahippocampal white matter. The pattern of white matter integrity disruption tends to follow an anterior to posterior gradient with greater damage noted in posterior regions in AD and MCI. Recent studies have exploited inter-voxel directional similarities to develop models of white matter pathways, and have used these models to assess the integrity of inter-cerebral connections. Particular focus has been applied to the parahippocampal white matter (including the perforant path) and the posterior cingulum. Although many studies have found DTI indicators of impaired white matter in AD and MCI, other studies have failed to detect any differences in MD or FA between the groups, demonstrating the need for large replicative studies. DTI is an evolving technique and advances in its application ought to provide new insights into AD and MCI.
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Affiliation(s)
- G T Stebbins
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612, USA.
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Liao MC, Ahmed M, Smith SO, Van Nostrand WE. Degradation of amyloid beta protein by purified myelin basic protein. J Biol Chem 2009; 284:28917-25. [PMID: 19692707 DOI: 10.1074/jbc.m109.050856] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The progressive accumulation of beta-amyloid (Abeta) in senile plaques and in the cerebral vasculature is the hallmark of Alzheimer disease and related disorders. Impaired clearance of Abeta from the brain likely contributes to the prevalent sporadic form of Alzheimer disease. Several major pathways for Abeta clearance include receptor-mediated cellular uptake, blood-brain barrier transport, and direct proteolytic degradation. Myelin basic protein (MBP) is the major structural protein component of myelin and plays a functional role in the formation and maintenance of the myelin sheath. MBP possesses endogenous serine proteinase activity and can undergo autocatalytic cleavage liberating distinct fragments. Recently, we showed that MBP binds Abeta and inhibits Abeta fibril formation (Hoos, M. D., Ahmed, M., Smith, S. O., and Van Nostrand, W. E. (2007) J. Biol. Chem. 282, 9952-9961; Hoos, M. D., Ahmed, M., Smith, S. O., and Van Nostrand, W. E. (2009) Biochemistry 48, 4720-4727). Here we show that Abeta40 and Abeta42 peptides are degraded by purified human brain MBP and recombinant human MBP, but not an MBP fragment that lacks autolytic activity. MBP-mediated Abeta degradation is inhibited by serine proteinase inhibitors. Similarly, Cos-1 cells expressing MBP degrade exogenous Abeta40 and Abeta42. In addition, we demonstrate that purified MBP also degrades assembled fibrillar Abeta in vitro. Mass spectrometry analysis identified distinct degradation products generated from Abeta digestion by MBP. Lastly, we demonstrate in situ that purified MBP can degrade parenchymal amyloid plaques as well as cerebral vascular amyloid that form in brain tissue of Abeta precursor protein transgenic mice. Together, these findings indicate that purified MBP possesses Abeta degrading activity in vitro.
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Affiliation(s)
- Mei-Chen Liao
- Department of Neurosurgery, Stony Brook University, Stony Brook, New York 11794-8122, USA
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Riederer IM, Schiffrin M, Kövari E, Bouras C, Riederer BM. Ubiquitination and cysteine nitrosylation during aging and Alzheimer's disease. Brain Res Bull 2009; 80:233-41. [PMID: 19427371 DOI: 10.1016/j.brainresbull.2009.04.018] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2009] [Revised: 04/26/2009] [Accepted: 04/26/2009] [Indexed: 10/20/2022]
Abstract
Protein oxidation and ubiquitination of brain proteins are part of mechanisms that modulate protein function or that inactivate proteins and target misfolded proteins to degradation. In this study, we focused on brain aging and on mechanism involved in neurodegeneration such as events occurring in Alzheimer's disease (AD). The goal was to identify differences in nitrosylated proteins - at cysteine residues, and in the composition of ubiquinated proteins between aging and Alzheimer's samples by using a proteomic approach. A polyclonal anti-S-nitrosyl-cysteine, a mono- and a polyclonal anti-ubiquitin antibody were used for the detection of modified or ubiquitinated proteins in middle-aged and aged human entorhinal autopsy brains tissues of 14 subjects without neurological signs and 8 Alzheimer's patients. Proteins were separated by one- and two-dimensional gel electrophoresis and analyzed by Coomassie blue and immuno-blot staining. We identified that the glial fibrillary acidic and tau proteins are more ubiquitinated in brain tissues of Alzheimer's patients. Furthermore, glial fibrillary proteins were also found in nitrosylated state and further characterized by 2D Western blots and identified. Since reactive astrocytes localized prominently around senile plaques one can speculate that elements of plaques such as beta-amyloid proteins may activate surrounding glial elements and proteins.
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Affiliation(s)
- Irène M Riederer
- Center for Psychiatric Neuroscience, Proteomics Unit, CHUV, 1008 Prilly-Lausanne, Switzerland.
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Gu F, Shi J, Wen Y, Fan H, Hu J, Hu Y, Zhao Z. Translational responses of NR2B overexpression in the cerebral cortex of transgenic mice: A liquid chromatography-based proteomic approach. Brain Res 2009; 1250:1-13. [DOI: 10.1016/j.brainres.2008.10.039] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2008] [Revised: 08/01/2008] [Accepted: 10/12/2008] [Indexed: 10/21/2022]
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Diffusion tractography of the fornix in schizophrenia. Schizophr Res 2009; 107:39-46. [PMID: 19046624 PMCID: PMC2646850 DOI: 10.1016/j.schres.2008.10.022] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2008] [Revised: 10/16/2008] [Accepted: 10/20/2008] [Indexed: 02/02/2023]
Abstract
BACKGROUND White matter fiber tracts, especially those interconnecting the frontal and temporal lobes, are likely implicated in pathophysiology of schizophrenia. Very few studies, however, have focused on the fornix, a compact bundle of white matter fibers, projecting from the hippocampus to the septum, anterior nucleus of the thalamus and the mamillary bodies. Diffusion Tensor Imaging (DTI), and a new post-processing method, fiber tractography, provides a unique opportunity to visualize and to quantify entire trajectories of fiber bundles, such as the fornix, in vivo. We applied these techniques to quantify fornix diffusion anisotropy in schizophrenia. METHODS DTI images were used to evaluate the left and the right fornix in 36 male patients diagnosed with chronic schizophrenia and 35 male healthy individuals, group matched on age, parental socioeconomic status, and handedness. Regions of interest were drawn manually, blind to group membership, to guide tractography, and fractional anisotropy (FA), a measure of fiber integrity, was calculated and averaged over the entire tract for each subject. The Doors and People test (DPT) was used to evaluate visual and verbal memory, combined recall and combined recognition. RESULTS Analysis of variance was performed and findings demonstrated a difference between patients with schizophrenia and controls for fornix FA (p=0.006). Protected post-hoc independent sample t-tests demonstrated a bilateral FA decrease in schizophrenia, compared with control subjects (left side: p=0.048; right side p=0.006). Higher fornix FA was statistically significantly correlated with DPT and measures of combined visual memory (r=0.554, p=0.026), combined verbal memory (r=0.647, p=0.007), combined recall (r=0.516, p=0.041), and combined recognition (r=0.710, p=0.002) for the control group. No such statistically significant correlations were found in the patient group. CONCLUSIONS Our findings show the utility of applying DTI and tractography to study white matter fiber tracts in vivo in schizophrenia. Specifically, we observed a bilateral disruption in fornix integrity in schizophrenia, thus broadening our understanding of the pathophysiology of this disease.
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Asamoto H, Ichibangase T, Uchikura K, Imai K. Application of an improved proteomics method, fluorogenic derivatization–liquid chromatography–tandem mass spectrometry, to differential analysis of proteins in small regions of mouse brain. J Chromatogr A 2008; 1208:147-55. [DOI: 10.1016/j.chroma.2008.08.078] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2008] [Revised: 08/19/2008] [Accepted: 08/22/2008] [Indexed: 11/25/2022]
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Le-Niculescu H, McFarland MJ, Ogden CA, Balaraman Y, Patel S, Tan J, Rodd ZA, Paulus M, Geyer MA, Edenberg HJ, Glatt SJ, Faraone SV, Nurnberger JI, Kuczenski R, Tsuang MT, Niculescu AB. Phenomic, convergent functional genomic, and biomarker studies in a stress-reactive genetic animal model of bipolar disorder and co-morbid alcoholism. Am J Med Genet B Neuropsychiatr Genet 2008; 147B:134-66. [PMID: 18247375 DOI: 10.1002/ajmg.b.30707] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We had previously identified the clock gene D-box binding protein (Dbp) as a potential candidate gene for bipolar disorder and for alcoholism, using a Convergent Functional Genomics (CFG) approach. Here we report that mice with a homozygous deletion of DBP have lower locomotor activity, blunted responses to stimulants, and gain less weight over time. In response to a chronic stress paradigm, these mice exhibit a diametric switch in these phenotypes. DBP knockout mice are also activated by sleep deprivation, similar to bipolar patients, and that activation is prevented by treatment with the mood stabilizer drug valproate. Moreover, these mice show increased alcohol intake following exposure to stress. Microarray studies of brain and blood reveal a pattern of gene expression changes that may explain the observed phenotypes. CFG analysis of the gene expression changes identified a series of novel candidate genes and blood biomarkers for bipolar disorder, alcoholism, and stress reactivity.
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Affiliation(s)
- H Le-Niculescu
- Laboratory of Neurophenomics, Indiana University School of Medicine, Indianapolis, Indiana
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Bartzokis G, Lu PH, Geschwind DH, Tingus K, Huang D, Mendez MF, Edwards N, Mintz J. Apolipoprotein E affects both myelin breakdown and cognition: implications for age-related trajectories of decline into dementia. Biol Psychiatry 2007; 62:1380-7. [PMID: 17659264 DOI: 10.1016/j.biopsych.2007.03.024] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2006] [Revised: 01/25/2007] [Accepted: 03/19/2007] [Indexed: 10/23/2022]
Abstract
BACKGROUND Age-related myelin breakdown is most evident in later-myelinating white matter (LMwm) brain regions. This process might degrade cognitive processing speed (CPS) underlying age-related cognitive decline and the predominance of age as a risk factor for Alzheimer's disease (AD). Apolipoprotein E (ApoE) 4 allele is the second most important AD risk factor. We tested the hypothesis that ApoE4 accelerates age-related slowing in CPS through the process of myelin breakdown. METHODS Calculated transverse relaxation rates (R(2)), an indirect magnetic resonance imaging measure of myelin breakdown in LMwm, and measures of CPS were obtained in 22 ApoE4+ and 80 ApoE4-, healthy "younger-old" individuals. To assess specificity, contrasting early-myelinating white matter region and memory task were also examined. RESULTS The CPS versus LMwm R(2) remained significant in the ApoE4+ group even after age was statistically adjusted (r = .65, p = .001) and differed from the correlation observed in the ApoE4- group (Fisher's z test = 3.22, p < .002). No significant associations were observed with the contrast region and memory task in either ApoE subgroup. CONCLUSIONS A specific association between CPS and myelin breakdown in LMwm exists in asymptomatic "younger-old" individuals at increased genetic risk for AD. Although inferences of change over time and causality are limited by the cross-sectional study design, this finding lends support to the hypotheses that myelin breakdown underlies age-related slowing in CPS and that by altering the trajectory of myelin breakdown, ApoE alleles shift the age at onset of cognitive decline. Combined use of biomarkers and CPS measures might be useful in developing and targeting primary prevention treatments for AD.
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Affiliation(s)
- George Bartzokis
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.
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Homma S, Jin X, Wang G, Tu N, Min J, Yanasak N, Mivechi NF. Demyelination, astrogliosis, and accumulation of ubiquitinated proteins, hallmarks of CNS disease in hsf1-deficient mice. J Neurosci 2007; 27:7974-86. [PMID: 17652588 PMCID: PMC6672719 DOI: 10.1523/jneurosci.0006-07.2007] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The heat shock transcription factors (Hsfs) are responsible for the heat shock response, an evolutionarily conserved process for clearance of damaged and aggregated proteins. In organisms such as Caenorhabditis elegans, which contain a single Hsf, reduction in the level of Hsf is associated with the appearance of age-related phenotypes and increased accumulation of protein aggregates. Mammalian cells express three hsfs (hsf1, hsf2, hsf4) and their role in CNS homeostasis remains unclear. In this study, we examined the effects of deletion of single or multiple hsf genes in the CNS using mutant mice. Our results show that hsf1-/- mice display progressive myelin loss that accompanies severe astrogliosis and this is exacerbated in the absence of either the hsf2 or hsf4 gene. Magnetic resonance imaging and behavioral studies indicate reduction in the white matter tracts of the corpus callosum, and deficiencies in motor activity, respectively, in aged hsf1-/- mice. Concomitantly, hsf1-/- aged CNS exhibit increased activated microglia and apoptotic cells that are mainly positive for GFAP, an astrocyte-specific marker. Studies based on the expression of short-lived ubiquitinated green fluorescent protein (GFPu) in living hsf1-/- cells indicate that they exhibit reduced ability to degrade ubiquitinated proteins, accumulate short-lived GFPu, and accumulate aggregates of the Huntington's model of GFP containing trinucleotide repeats (Q103-GFP). Likewise, hsf1-/- brain and astrocytes exhibit higher than wild-type levels of ubiquitinated proteins, increased levels of protein oxidation, and increased sensitivity to oxidative stress. These studies indicate a critical role for mammalian hsf genes, but specifically hsf1, in the quality control mechanisms and maintenance of CNS homeostasis during the organism's lifetime.
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Affiliation(s)
- Sachiko Homma
- Center for Molecular Chaperone/Radiobiology and Cancer Virology
| | - Xiongjie Jin
- Center for Molecular Chaperone/Radiobiology and Cancer Virology
| | - Guanghu Wang
- Center for Molecular Chaperone/Radiobiology and Cancer Virology
| | - Naxin Tu
- Center for Molecular Chaperone/Radiobiology and Cancer Virology
| | - Jinna Min
- Center for Molecular Chaperone/Radiobiology and Cancer Virology
| | - Nathan Yanasak
- Department of Radiology, Medical College of Georgia, Augusta, Georgia 30912
| | - Nahid F. Mivechi
- Center for Molecular Chaperone/Radiobiology and Cancer Virology
- Department of Radiology, Medical College of Georgia, Augusta, Georgia 30912
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Bartzokis G. Acetylcholinesterase inhibitors may improve myelin integrity. Biol Psychiatry 2007; 62:294-301. [PMID: 17070782 DOI: 10.1016/j.biopsych.2006.08.020] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2006] [Revised: 07/28/2006] [Accepted: 08/21/2006] [Indexed: 12/27/2022]
Abstract
Recent clinical trials have revealed that cholinergic treatments are efficacious in a wide spectrum of neuropsychiatric disorders that span the entire human lifespan and include disorders without cholinergic deficits. Furthermore, some clinical and epidemiological data suggest that cholinergic treatments have disease modifying/preventive effects. It is proposed that these observations can be usefully understood in a myelin-centered model of the human brain. The model proposes that the human brain's extensive myelination is the central evolutionary change that defines our uniqueness as a species and our unique vulnerability to highly prevalent neuropsychiatric disorders. Within the framework of this model the clinical, biochemical, and epidemiologic data can be reinterpreted to suggest that nonsynaptic effects of cholinergic treatments on the process of myelination and myelin repair contributes to their mechanism of action and especially to their disease modifying/preventive effects. The ability to test the model in human populations with safe and noninvasive imaging technologies makes it possible to undertake novel clinical trial efforts directed at primary prevention of some of the most prevalent and devastating of human disorders.
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Affiliation(s)
- George Bartzokis
- Department of Neurology, The Laboratory of Neuroimaging in the Division of Brain Mapping, The David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095-1769, USA.
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Hinman JD, Abraham CR. What's behind the decline? The role of white matter in brain aging. Neurochem Res 2007; 32:2023-31. [PMID: 17447140 DOI: 10.1007/s11064-007-9341-x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2007] [Accepted: 03/23/2007] [Indexed: 02/05/2023]
Abstract
The specific molecular events that underlie the age-related loss of cognitive function are poorly understood. Although not experimentally substantiated, age-dependent neuronal loss has long been considered central to age-related cognitive decline. More recently, age-related changes in brain white matter have taken precedence in explaining the steady decline in cognitive domains seen in non-diseased elderly. Characteristic alterations in the ultrastructure of myelin coupled with evidence of inflammatory processes present in the white matter of several different species suggest that specific molecular events within brain white matter may better explain observed pathological changes and cognitive deficits. This review focuses on recent evidence highlighting the importance of white matter in deciphering the course of "normal" brain aging.
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Affiliation(s)
- Jason D Hinman
- Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118, USA
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Le-Niculescu H, Balaraman Y, Patel S, Tan J, Sidhu K, Jerome RE, Edenberg HJ, Kuczenski R, Geyer MA, Nurnberger JI, Faraone SV, Tsuang MT, Niculescu AB. Towards understanding the schizophrenia code: an expanded convergent functional genomics approach. Am J Med Genet B Neuropsychiatr Genet 2007; 144B:129-58. [PMID: 17266109 DOI: 10.1002/ajmg.b.30481] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Identifying genes for schizophrenia through classical genetic approaches has proven arduous. Here, we present a comprehensive convergent analysis that translationally integrates brain gene expression data from a relevant pharmacogenomic mouse model (involving treatments with a psychomimetic agent - phencyclidine (PCP), and an anti-psychotic - clozapine), with human genetic linkage data and human postmortem brain data, as a Bayesian strategy of cross validating findings. Topping the list of candidate genes, we have three genes involved in GABA neurotransmission (GABRA1, GABBR1, and GAD2), one gene involved in glutamate neurotransmission (GRIA2), one gene involved in neuropeptide signaling (TAC1), two genes involved in synaptic function (SYN2 and KCNJ4), six genes involved in myelin/glial function (CNP, MAL, MBP, PLP1, MOBP and GFAP), and one gene involved in lipid metabolism (LPL). These data suggest that schizophrenia is primarily a disorder of brain functional and structural connectivity, with GABA neurotransmission playing a prominent role. These findings may explain the EEG gamma band abnormalities detected in schizophrenia. The analysis also revealed other high probability candidates genes (neurotransmitter signaling, other structural proteins, ion channels, signal transduction, regulatory enzymes, neuronal migration/neurite outgrowth, clock genes, transcription factors, RNA regulatory genes), pathways and mechanisms of likely importance in pathophysiology. Some of the pathways identified suggest possible avenues for augmentation pharmacotherapy of schizophrenia with other existing agents, such as benzodiazepines, anticonvulsants and lipid modulating agents. Other pathways are new potential targets for drug development. Lastly, a comparison with our earlier work on bipolar disorder illuminates the significant molecular overlap between schizophrenia and bipolar disorder.
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Affiliation(s)
- H Le-Niculescu
- Laboratory of Neurophenomics, Indiana University School of Medicine, Indianapolis, Indiana, USA
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Magaki S, Raghavan R, Mueller C, Oberg KC, Vinters HV, Kirsch WM. Iron, copper, and iron regulatory protein 2 in Alzheimer's disease and related dementias. Neurosci Lett 2007; 418:72-6. [PMID: 17408857 PMCID: PMC1955223 DOI: 10.1016/j.neulet.2007.02.077] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2006] [Revised: 02/27/2007] [Accepted: 02/28/2007] [Indexed: 11/28/2022]
Abstract
Accumulating evidence implicates a role for altered iron and copper metabolism in the pathogenesis of neurodegenerative disorders such as Alzheimer's disease (AD). However, imbalances in the levels of the various forms of iron at different stages of AD have not been examined. In this pilot study we extracted and measured the levels of loosely bound, non-heme and total iron and copper in the frontal cortex and hippocampus of patients with mild-moderate AD (n=3), severe AD (n=8) and dementia with Lewy bodies (DLB, n=6), using graphite furnace atomic absorption spectrometry (GFAAS). Additionally, the expression of iron regulatory protein 2 (IRP2) was examined in relation to the pathological hallmarks of AD and DLB, amyloid plaques, neurofibrillary tangles (NFT), and Lewy bodies, by immunohistochemistry. We found significantly decreased loosely bound iron in the hippocampal white matter of mild-moderate and severe AD patients and a trend towards increased non-heme iron in the hippocampal gray matter of severe AD patients. Furthermore, decreased levels of total copper were seen in severe AD and DLB frontal cortex compared to controls, suggesting an imbalance in brain metal levels in both AD and DLB. The decrease in loosely bound iron in mild-moderate AD patients may be associated with myelin breakdown seen in the beginning stages of AD and implicates that iron dysregulation is an early event in AD pathogenesis.
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Affiliation(s)
- Shino Magaki
- Center for Neurosurgery Research, Loma Linda University, Loma Linda, CA, USA
| | - Ravi Raghavan
- Neuropathology Section, Department of Pathology, Loma Linda University, Loma Linda, CA, USA
| | - Claudius Mueller
- Center for Neurosurgery Research, Loma Linda University, Loma Linda, CA, USA
| | - Kerby C. Oberg
- Department of Pathology and Human Anatomy, Loma Linda University, Loma Linda, CA, USA
| | - Harry V. Vinters
- Section of Neuropathology, Department of Neurology, University of California, Los Angeles, CA, USA
| | - Wolff M. Kirsch
- Center for Neurosurgery Research, Loma Linda University, Loma Linda, CA, USA
- *CORRESPONDING AUTHOR: Wolff M. Kirsch, M.D. , phone: 909-558-7070, FAX: 909-558-0472, Address: Loma Linda University, Coleman Pavilion, 1175 Campus Street, Suite 11113, Loma Linda, California 92350
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Brandt I, De Vriendt K, Devreese B, Van Beeumen J, Van Dongen W, Augustyns K, De Meester I, Scharpé S, Lambeir AM. Search for substrates for prolyl oligopeptidase in porcine brain. Peptides 2005; 26:2536-46. [PMID: 15996789 DOI: 10.1016/j.peptides.2005.05.016] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2005] [Revised: 05/23/2005] [Accepted: 05/23/2005] [Indexed: 11/17/2022]
Abstract
The function of prolyl oligopeptidase (PO) has been associated with several disorders of the central nervous system. The purpose of this study was to identify endogenous substrates for recombinant porcine PO in porcine brain. The smaller polypeptides were extracted from total brain homogenates and fractionated by two-dimensional chromatography prior to incubation with PO. Shifts in the mass spectrum between the control and the incubated sample, marked potential substrates. Using MSMS peptide sequencing techniques, we identified several fragments of intracellular proteins as potential substrates, which opens new perspectives for finding the function of PO in the intracellular space.
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Affiliation(s)
- Inger Brandt
- Laboratory of Medical Biochemistry, Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
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Quan L, Ishikawa T, Michiue T, Li DR, Zhao D, Zhu BL, Maeda H. Quantitative morphometry of granular ‘dot-like’ ubiquitin-immunoreactivity in the crus cerebri in asphyxiation and fire fatalities. Leg Med (Tokyo) 2005; 7:81-8. [PMID: 15708330 DOI: 10.1016/j.legalmed.2004.08.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2004] [Revised: 08/12/2004] [Accepted: 08/23/2004] [Indexed: 10/26/2022]
Abstract
In the central nervous system (CNS), a variety of ubiquitinated structures have been reported, usually as pathological alterations of the brain related to degenerative diseases or aging. However, previous studies showed an increase in the ubiquitin (Ub)-immunoreactive intranuclear inclusion of the pigmented neurons of the substantia nigra in the midbrain in asphyxiation and fire fatalities in the adult subjects. The aim of the present study was to examine granular 'dot-like' Ub-immunoreactivity in the crus cerebri (cortico-spinal tracts) in related fatalities (over 35 years of age, n=169), including fatal asphyxiation (n=27), drownings (n=14), fire fatalities (n=60), and control groups (n=68). Dot-like Ub-immunoreactivity was clearly observed in the descending tract of the crus cerebri. Morphometric analysis of the positive granular area (dot-like Ub-area) showed a higher value in strangulation and fire fatalities and a lower value in hemorrhagic and head injury deaths, as was observed for the inclusion-type neuronal Ub-positivity. However, there was a difference between those markers: a low value was seen for the inclusion-type neuronal Ub-positivity in hanging and drownings, and a difference in the dot-like Ub-area was detected between fire fatalities with lower and higher COHb levels. Our findings suggested the possible usefulness of these markers for examination of CNS stress responses in traumas, at least in middle-aged and elderly victims and a partial difference in stress reaction between the cortico-spinal tracts and dopaminergic neurons.
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Affiliation(s)
- Li Quan
- Department of Legal Medicine, Osaka City University Medical School, Abeno, 545-8585 Osaka, Japan
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50
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Patchev VK, Schroeder J, Goetz F, Rohde W, Patchev AV. Neurotropic action of androgens: principles, mechanisms and novel targets. Exp Gerontol 2004; 39:1651-60. [PMID: 15582281 DOI: 10.1016/j.exger.2004.07.011] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2004] [Accepted: 07/07/2004] [Indexed: 11/20/2022]
Abstract
The importance of androgen signaling is well recognized for numerous aspects of central nervous system (CNS) function, ranging from sex-specific organization of neuroendocrine and behavioral circuits to adaptive capacity, resistance and repair. Nonetheless, concepts for the therapeutic use of androgens in neurological and mental disorders are far from being established. This review outlines some critical issues which interfere with decisions on the suitability of androgens as therapeutic agents for CNS conditions. Among these, sex-specific organization of neural substrates and resulting differential responsiveness to endogenous gonadal steroids, convergence of steroid hormone actions on common molecular targets, co-presence of different sex steroid receptors in target neuronal populations, and in situ biotransformation of natural androgens apparently pose the principal obstacles for the characterization of specific neurotropic effects of androgens. Additional important, albeit less explored aspects consist in insufficient knowledge about molecular targets in the CNS which are under exclusive or predominant androgen control. Own experimental data illustrate the variability of pharmacological effects of natural and synthetic androgens on CNS functions of adaptive relevance, such as sexual behavior, anxiety and endocrine responsiveness to stress. Finally, we present results from an analysis of the consequences of aging for the rat brain transcriptome and examination of the influence of androgens on differentially expressed genes with presumable significance in neuropathology.
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Affiliation(s)
- Vladimir K Patchev
- Male Health Care 2, Corporate Research Gynecology and Andrology, Schering AG/Jenapharm, Otto-Schott-Str. 15, D-07745 Jena, Germany.
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