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Yu Y, Chen R, Mao K, Deng M, Li Z. The Role of Glial Cells in Synaptic Dysfunction: Insights into Alzheimer's Disease Mechanisms. Aging Dis 2024; 15:459-479. [PMID: 37548934 PMCID: PMC10917533 DOI: 10.14336/ad.2023.0718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 07/18/2023] [Indexed: 08/08/2023] Open
Abstract
Alzheimer's disease (AD) is a devastating neurodegenerative disorder that impacts a substantial number of individuals globally. Despite its widespread prevalence, there is currently no cure for AD. It is widely acknowledged that normal synaptic function holds a key role in memory, cognitive abilities, and the interneuronal transfer of information. As AD advances, symptoms including synaptic impairment, decreased synaptic density, and cognitive decline become increasingly noticeable. The importance of glial cells in the formation of synapses, the growth of neurons, brain maturation, and safeguarding the microenvironment of the central nervous system is well recognized. However, during AD progression, overactive glial cells can cause synaptic dysfunction, neuronal death, and abnormal neuroinflammation. Both neuroinflammation and synaptic dysfunction are present in the early stages of AD. Therefore, focusing on the changes in glia-synapse communication could provide insights into the mechanisms behind AD. In this review, we aim to provide a summary of the role of various glial cells, including microglia, astrocytes, oligodendrocytes, and oligodendrocyte precursor cells, in regulating synaptic dysfunction. This may offer a new perspective on investigating the underlying mechanisms of AD.
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Affiliation(s)
- Yang Yu
- Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China.
| | - Ran Chen
- Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China.
- School of Medicine, Sun Yat-sen University, Shenzhen, China.
| | - Kaiyue Mao
- Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China.
- School of Medicine, Sun Yat-sen University, Shenzhen, China.
| | - Maoyan Deng
- Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China.
- School of Medicine, Sun Yat-sen University, Shenzhen, China.
| | - Zhigang Li
- Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China.
- Shenzhen Key Laboratory of Chinese Medicine Active Substance Screening and Translational Research, Shenzhen, China.
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Pragati, Sarkar S. Reinstated Activity of Human Tau-induced Enhanced Insulin Signaling Restricts Disease Pathogenesis by Regulating the Functioning of Kinases/Phosphatases and Tau Hyperphosphorylation in Drosophila. Mol Neurobiol 2024; 61:982-1001. [PMID: 37674037 DOI: 10.1007/s12035-023-03599-y] [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: 04/04/2023] [Accepted: 08/18/2023] [Indexed: 09/08/2023]
Abstract
Tauopathies such as Alzheimer's disease (AD), Frontotemporal dementia, and parkinsonism linked to chromosome 17 (FTDP-17), etc. are characterized by tau hyperphosphorylation and distinguished accumulation of paired helical filaments (PHFs)/or neurofibrillary tangles (NFTs) in a specific-neuronal subset of the brain. Among different reported risk factors, type 2 diabetes (T2D) has gained attention due to its correlation with tau pathogenesis. However, mechanistic details and the precise contribution of insulin pathway in tau etiology is still debatable. We demonstrate that expression of human tau causes overactivation of insulin pathway in Drosophila disease models. We subsequently noted that tissue-specific downregulation of insulin signaling or even exclusive reduction of its growth-promoting sub-branch effectively reinstates the overactivated insulin signaling pathway in human tau expressing cells, which in turn restricts pathogenic tau hyperphosphorylation and aggregate formation. It was further noted that restored tau phosphorylation was achieved due to a reestablished balance between the levels of different kinase(s) (GSK3β and ERK/P38 MAP kinase) and phosphatase (PP2A). Taken together, our study demonstrates a precise involvement of the insulin pathway and associated molecular events in the pathogenesis of human tauopathies in Drosophila, which will be immensely helpful in developing novel therapeutic options against these devastating human brain disorders. Moreover, our study reveals an interesting link between tau etiology and aberrant insulin signaling, which is a characteristic feature of Type 2 Diabetes.
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Affiliation(s)
- Pragati
- Department of Genetics, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India
| | - Surajit Sarkar
- Department of Genetics, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India.
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3
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Cis-p-tau plays crucial role in lysolecithin-induced demyelination and subsequent axonopathy in mouse optic chiasm. Exp Neurol 2023; 359:114262. [PMID: 36343678 DOI: 10.1016/j.expneurol.2022.114262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 10/21/2022] [Accepted: 10/31/2022] [Indexed: 11/06/2022]
Abstract
Multiple sclerosis (MS) is an autoimmune demyelinating disease that leads to axon degeneration as the major cause of everlasting neurological disability. The cis-phosphorylated tau (cis-p-tau) is an isoform of tau phosphorylated on threonine 231 and causes tau fails to bind micro-tubules and promotes assembly. It gains toxic function and forms tangles in the cell which finally leads to cell death. An antibody raised against cis- p-tau (cis mAb) detects this isoform and induces its clearance. Here, we investigated the formation of cis-p-tau in a lysophosphatidylcholine (LPC)-induced prolonged demyelination model as well as the beneficial effects of its clearance using cis mAb. Cis -p-tau was increased in the lesion site, especially in axons and microglia. Behavioral and functional studies were performed using visual cliff test, visual placing test, and visual evoked potential recording. Cis-p-tau clearance resulted in decreased gliosis, protected myelin and reduced axon degeneration. Analysis of behavioral and electrophysiological data showed that clearance of cis-p-tau by cis mAb treatment improved the visual acuity along with the integrity of the optic pathway. Our results highlight the opportunity of using cis mAb as a new therapy for protecting myelin and axons in patients suffering from MS.
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Goel H, Goyal K, Pandey AK, Benjamin M, Khan F, Pandey P, Mittan S, Iqbal D, Alsaweed M, Alturaiki W, Madkhali Y, Kamal MA, Tanwar P, Upadhyay TK. Elucidations of Molecular Mechanism and Mechanistic Effects of Environmental Toxicants in Neurological Disorders. CNS & NEUROLOGICAL DISORDERS DRUG TARGETS 2023; 22:84-97. [PMID: 35352654 DOI: 10.2174/1871527321666220329103610] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 02/08/2022] [Accepted: 02/08/2022] [Indexed: 02/08/2023]
Abstract
Due to rising environmental and global public health concerns associated with environmental contamination, human populations are continually being exposed to environmental toxicants, including physical chemical mutagens widespread in our environment causing adverse consequences and inducing a variety of neurological disorders in humans. Physical mutagens comprise ionizing and non-ionizing radiation, such as UV rays, IR rays, X-rays, which produces a broad spectrum of neuronal destruction, including neuroinflammation, genetic instability, enhanced oxidative stress driving mitochondrial damage in the human neuronal antecedent cells, cognitive impairment due to alterations in neuronal function, especially in synaptic plasticity, neurogenesis repression, modifications in mature neuronal networks drives to enhanced neurodegenerative risk. Chemical Mutagens including alkylating agents (EMS, NM, MMS, and NTG), Hydroxylamine, nitrous acid, sodium azide, halouracils are the major toxic mutagen in our environment and have been associated with neurological disorders. These chemical mutagens create dimers of pyrimidine that cause DNA damage that leads to ROS generation producing mutations, chromosomal abnormalities, genotoxicity which leads to increased neurodegenerative risk. The toxicity of four heavy metal including Cd, As, Pb, Hg is mostly responsible for complicated neurological disorders in humans. Cadmium exposure can enhance the permeability of the BBB and penetrate the brain, driving brain intracellular accumulation, cellular dysfunction, and cerebral edema. Arsenic exerts its toxic effect by induction of ROS production in neuronal cells. In this review, we summarize the molecular mechanism and mechanistic effects of mutagens in the environment and their role in multiple neurological disorders.
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Affiliation(s)
- Harsh Goel
- Department of Laboratory Oncology, All India Institute of Medical Sciences, New Delhi, India
| | - Keshav Goyal
- Division of Molecular and Cellular Biology, Faculty of Biology, Ludwig Maximilians Universitat, Munchen, Germany
| | - Avanish Kumar Pandey
- Department of Laboratory Oncology, All India Institute of Medical Sciences, New Delhi, India
| | - Mercilena Benjamin
- Department of Laboratory Oncology, All India Institute of Medical Sciences, New Delhi, India
| | - Fahad Khan
- Department of Biotechnology, Noida Institute of Engineering & Technology, 19, Knowledge Park-II, Institutional Area, Greater Noida, India
| | - Pratibha Pandey
- Department of Biotechnology, Noida Institute of Engineering & Technology, 19, Knowledge Park-II, Institutional Area, Greater Noida, India
| | - Sandeep Mittan
- Department of Cardiology, Ichan School of Medicine, Mount Sinai Hospital, One Gustave L. Levy Place, New York, USA
| | - Danish Iqbal
- Department of Medical Laboratory Sciences, College of Applied Medical Sciences, Majmaah University, Al-Majmaah, 11952, Saudi Arabia
| | - Mohammed Alsaweed
- Department of Medical Laboratory Sciences, College of Applied Medical Sciences, Majmaah University, Al-Majmaah, 11952, Saudi Arabia
| | - Wael Alturaiki
- Department of Medical Laboratory Sciences, College of Applied Medical Sciences, Majmaah University, Al-Majmaah, 11952, Saudi Arabia
| | - Yahya Madkhali
- Department of Medical Laboratory Sciences, College of Applied Medical Sciences, Majmaah University, Al-Majmaah, 11952, Saudi Arabia
| | - Mohammad Amjad Kamal
- Institutes for Systems Genetics, Frontiers Science Center for Disease-related Molecular Network, West China Hospital, Sichuan University, China
- King Fahd Medical Research Center, King Abdulaziz University, Saudi Arabia
- Department of Pharmacy, Faculty of Allied Health Sciences, Daffodil International University, Bangladesh
- Enzymoics, 7 Peterlee Place, Hebersham NSW 2770, Novel Global Community Educational Foundation, Australia
| | - Pranay Tanwar
- Department of Laboratory Oncology, All India Institute of Medical Sciences, New Delhi, India
| | - Tarun Kumar Upadhyay
- Department of Biotechnology, Parul Institute of Applied Sciences and Cell Culture and Immunobiochemistry Lab, Centre of Research for Development, Parul University, Vadodara, Gujarat 391760, India
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Rubinski A, Franzmeier N, Dewenter A, Luan Y, Smith R, Strandberg O, Ossenkoppele R, Dichgans M, Hansson O, Ewers M. Higher levels of myelin are associated with higher resistance against tau pathology in Alzheimer’s disease. Alzheimers Res Ther 2022; 14:139. [PMID: 36153607 PMCID: PMC9508747 DOI: 10.1186/s13195-022-01074-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 08/28/2022] [Indexed: 11/10/2022]
Abstract
Background In Alzheimer’s disease (AD), fibrillar tau initially occurs locally and progresses preferentially between closely connected regions. However, the underlying sources of regional vulnerability to tau pathology remain unclear. Previous brain-autopsy findings suggest that the myelin levels—which differ substantially between white matter tracts in the brain—are a key modulating factor of region-specific susceptibility to tau deposition. Here, we investigated whether myelination differences between fiber tracts of the human connectome are predictive of the interregional spreading of tau pathology in AD. Methods We included two independently recruited samples consisting of amyloid-PET-positive asymptomatic and symptomatic elderly individuals, in whom tau-PET was obtained at baseline (ADNI: n = 275; BioFINDER-1: n = 102) and longitudinally in a subset (ADNI: n = 123, mean FU = 1.53 [0.69–3.95] years; BioFINDER-1: n = 39, mean FU = 1.87 [1.21–2.78] years). We constructed MRI templates of the myelin water fraction (MWF) in 200 gray matter ROIs and connecting fiber tracts obtained from adult cognitively normal participants. Using the same 200 ROI brain-parcellation atlas, we obtained tau-PET ROI values from each individual in ADNI and BioFINDER-1. In a spatial regression analysis, we first tested the association between cortical myelin and group-average tau-PET signal in the amyloid-positive and control groups. Secondly, employing a previously established approach of modeling tau-PET spreading based on functional connectivity between ROIs, we estimated in a linear regression analysis, whether the level of fiber-tract myelin modulates the association between functional connectivity and longitudinal tau-PET spreading (i.e., covariance) between ROIs. Results We found that higher myelinated cortical regions show lower tau-PET uptake (ADNI: rho = − 0.267, p < 0.001; BioFINDER-1: rho = − 0.175, p = 0.013). Fiber-tract myelin levels modulated the association between functional connectivity and tau-PET spreading, such that at higher levels of fiber-tract myelin, the association between stronger connectivity and higher covariance of tau-PET between the connected ROIs was attenuated (interaction fiber-tract myelin × functional connectivity: ADNI: β = − 0.185, p < 0.001; BioFINDER-1: β = − 0.166, p < 0.001). Conclusion Higher levels of myelin are associated with lower susceptibility of the connected regions to accumulate fibrillar tau. These results enhance our understanding of brain substrates that explain regional variation in tau accumulation and encourage future studies to investigate potential underlying mechanisms. Supplementary Information The online version contains supplementary material available at 10.1186/s13195-022-01074-9.
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LoPresti P. Serum-Based Biomarkers in Neurodegeneration and Multiple Sclerosis. Biomedicines 2022; 10:biomedicines10051077. [PMID: 35625814 PMCID: PMC9138270 DOI: 10.3390/biomedicines10051077] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 04/27/2022] [Accepted: 04/29/2022] [Indexed: 02/04/2023] Open
Abstract
Multiple Sclerosis (MS) is a debilitating disease with typical onset between 20 and 40 years of age, so the disability associated with this disease, unfortunately, occurs in the prime of life. At a very early stage of MS, the relapsing-remitting mobility impairment occurs in parallel with a progressive decline in cognition, which is subclinical. This stage of the disease is considered the beginning of progressive MS. Understanding where a patient is along such a subclinical phase could be critical for therapeutic efficacy and enrollment in clinical trials to test drugs targeted at neurodegeneration. Since the disease course is uneven among patients, biomarkers are needed to provide insights into pathogenesis, diagnosis, and prognosis of events that affect neurons during this subclinical phase that shapes neurodegeneration and disability. Thus, subclinical cognitive decline must be better understood. One approach to this problem is to follow known biomarkers of neurodegeneration over time. These biomarkers include Neurofilament, Tau and phosphotau protein, amyloid-peptide-β, Brl2 and Brl2-23, N-Acetylaspartate, and 14-3-3 family proteins. A composite set of these serum-based biomarkers of neurodegeneration might provide a distinct signature in early vs. late subclinical cognitive decline, thus offering additional diagnostic criteria for progressive neurodegeneration and response to treatment. Studies on serum-based biomarkers are described together with selective studies on CSF-based biomarkers and MRI-based biomarkers.
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Affiliation(s)
- Patrizia LoPresti
- Department of Psychology, The University of Illinois at Chicago, 1007 West Harrison Street, Chicago, IL 60607, USA
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Yun HS, Oh J, Lim JS, Kim HJ, Kim JS. Anti-Inflammatory Effect of Wasp Venom in BV-2 Microglial Cells in Comparison with Bee Venom. INSECTS 2021; 12:insects12040297. [PMID: 33805372 PMCID: PMC8066097 DOI: 10.3390/insects12040297] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 03/23/2021] [Accepted: 03/25/2021] [Indexed: 12/14/2022]
Abstract
Simple Summary As the population of the yellow-legged hornet (Vespa velutina) spreads, this study investigated ways to utilize this resource of abundant invasive wasp species. Hymenoptera venoms, including bee venom and wasp venom, have therapeutic potential. Although the venoms are toxic to humans, the elucidation of their composition and working mechanisms has led to discoveries about their potential applications in treatment modalities for a variety of disorders. Therefore, we examined the anti-inflammatory effect of wasp venom from V. velutina in comparison with that of bee venom from honey bee on BV-2 murine microglial cells. Treatment with wasp venom reduced the secretion of nitric oxide and pro-inflammatory cytokines, including interleukin-6 and tumor necrosis factor alpha, from BV-2 cells activated by lipopolysaccharide (LPS). Western blot analysis revealed that wasp venom and bee venom decreased the expression levels of inflammation markers, including inducible nitric oxide synthase and cyclooxygenase-2. In addition, wasp venom decreased the nuclear translocation of nuclear factor κB (NF-κB), which is a key transcription factor in the regulation of cellular inflammatory response. Overall, the findings demonstrated that wasp venom inhibited LPS-induced inflammation in microglial cells by suppressing the NF-κB-mediated signaling pathway, which warrants further studies to confirm its therapeutic potential for neurodegenerative diseases. Abstract The aim of this study was to compare the anti-inflammatory effect of wasp venom (WV) from the yellow-legged hornet (Vespa velutina) with that of bee venom (BV) on BV-2 murine microglial cells. WV was collected from the venom sac, freeze-dried, and used for in vitro examinations. WV and BV were non-toxic to BV-2 cells at concentrations of 160 and 12 µg/mL or lower, respectively. Treatment with WV reduced the secretion of nitric oxide and proinflammatory cytokines, including interleukin-6 and tumor necrosis factor alpha, from BV-2 cells activated by lipopolysaccharide (LPS). Western blot analysis revealed that WV and BV decreased the expression levels of inflammation markers, including inducible nitric oxide synthase and cyclooxygenase-2. In addition, WV decreased the nuclear translocation of nuclear factor κB (NF-κB), which is a key transcription factor in the regulation of cellular inflammatory response. Cumulatively, the results demonstrated that WV inhibited LPS-induced neuroinflammation in microglial cells by suppressing the NF-κB-mediated signaling pathway, which warrants further studies to confirm its therapeutic potential for neurodegenerative diseases.
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Affiliation(s)
- Hyun Seok Yun
- School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Korea;
| | - Jisun Oh
- Institute of Agriculture Science and Technology, Kyungpook National University, Daegu 41566, Korea; (J.O.); (J.S.L.)
| | - Ji Sun Lim
- Institute of Agriculture Science and Technology, Kyungpook National University, Daegu 41566, Korea; (J.O.); (J.S.L.)
| | - Hyo Jung Kim
- National Institute for Korean Medicine Development, Gyeongsan 38540, Korea;
| | - Jong-Sang Kim
- School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Korea;
- Institute of Agriculture Science and Technology, Kyungpook National University, Daegu 41566, Korea; (J.O.); (J.S.L.)
- Correspondence: ; Tel.: +82-53-950-5752; Fax: +82-53-950-6750
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Pakzad D, Akbari V, Sepand MR, Aliomrani M. Risk of neurodegenerative disease due to tau phosphorylation changes and arsenic exposure via drinking water. Toxicol Res (Camb) 2021; 10:325-333. [PMID: 33884182 PMCID: PMC8045564 DOI: 10.1093/toxres/tfab011] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 12/28/2020] [Accepted: 01/24/2021] [Indexed: 12/12/2022] Open
Abstract
It is estimated that around 140 million people are drinking highly contaminated water with arsenic (As) as a natural earth's crust component. On the other hand, the prevalence of neurodegenerative disorders, especially Alzheimer's disease, is constantly increasing. The aim of the present study was to investigate the correlation between oral arsenic trioxide exposure and its impact on tau protein phosphorylation at Ser262. Fifty-four male mice were randomly divided into three groups and were freely accessed to food and contaminated water of 1 and 10 ppm arsenic trioxide for 3 months, except for control subjects. At the end of each month, As concentration and tau phosphorylation were checked with graphite furnace atomic absorption spectrometer and western blot analysis, respectively. Surprisingly, it was observed that the amount of measured brain arsenic in 10 ppm-exposed subjects was significantly increased after 3 months (P-value ˂ 0.0001). The significant changes in tau phosphorylation were not seen in the 1 ppm-exposed subjects, and it was observed that Ser262 phosphorylation significantly increased after 2 and 3 months in the 10 ppm group (P-value < 0.05). Our results demonstrated that arsenic accumulated in the brain time-dependently and increased Ser262 tau phosphorylation, which is very important in several tauopathies. In conclusion, it could be inferred that environmental arsenic exposure even at very low concentrations could be considered as a reason for increasing the risk of developing neurodegenerative disease.
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Affiliation(s)
- Davoud Pakzad
- Isfahan University of Medical Sciences and Health Services, Isfahan 81746-73461, Iran
| | - Vajihe Akbari
- Department of Pharmaceutical Biotechnology, School of Pharmacy, Isfahan University of Medical Sciences and Health Services, Isfahan 81746-73461, Iran
| | - Mohammad Reza Sepand
- Department of Toxicology and Pharmacology, School of Pharmacy and Pharmaceutical Sciences, Tehran University of Medical Sciences and Health Services, Tehran 81746-73461, Iran
| | - Mehdi Aliomrani
- Department of Toxicology and Pharmacology, Isfahan Pharmaceutical Sciences Research Center, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences and Health Services, Isfahan 81746-73461, Iran
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Tau at the interface between neurodegeneration and neuroinflammation. Genes Immun 2020; 21:288-300. [PMID: 33011744 DOI: 10.1038/s41435-020-00113-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 09/16/2020] [Accepted: 09/22/2020] [Indexed: 12/21/2022]
Abstract
Tau is an evolutionary conserved protein that promotes the assembly and stabilization of microtubules in neuronal axons. Complex patterns of posttranslational modifications (PTMs) dynamically regulate tau biochemical properties and consequently its functions. An imbalance in tau PTMs has been connected with a broad spectrum of neurodegenerative conditions which are collectively known as tauopathies and include Alzheimer's disease (AD), progressive supranuclear palsy (PSP), and corticobasal degeneration (CBD) among others. The hallmark of these neurological disorders is the presence in the brain of fibrillary tangles constituted of misfolded species of hyper-phosphorylated tau. The pathological events leading to tau aggregation are still largely unknown but increasing evidence suggests that neuroinflammation plays a critical role in tangle formation. Moreover, tau aggregation itself could enhance inflammation through feed-forward mechanisms, amplifying the initial neurotoxic insults. Protective effects of tau against neuroinflammation have been also documented, adding another layer of complexity to this phenomenon. Here, we will review the current knowledge on tau regulation and function in health and disease. In particular, we will address its emerging role in connecting neurodegenerative and neuroinflammatory processes.
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LoPresti P. Tau in Oligodendrocytes Takes Neurons in Sickness and in Health. Int J Mol Sci 2018; 19:ijms19082408. [PMID: 30111714 PMCID: PMC6121290 DOI: 10.3390/ijms19082408] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 08/05/2018] [Accepted: 08/06/2018] [Indexed: 12/31/2022] Open
Abstract
Oligodendrocytes (OLGs), the myelin-forming cells of the central nervous system (CNS), are lifelong partners of neurons. They adjust to the functional demands of neurons over the course of a lifetime to meet the functional needs of a healthy CNS. When this functional interplay breaks down, CNS degeneration follows. OLG processes are essential features for OLGs being able to connect with the neurons. As many as fifty cellular processes from a single OLG reach and wrap an equal number of axonal segments. The cellular processes extend to meet and wrap axonal segments with myelin. Further, transport regulation, which is critical for myelination, takes place within the cellular processes. Because the microtubule-associated protein tau plays a crucial role in cellular process extension and myelination, alterations of tau in OLGs have deleterious effects, resulting in neuronal malfunction and CNS degeneration. Here, we review current concepts on the lifelong role of OLGs and myelin for brain health and plasticity. We present key studies of tau in OLGs and select important studies of tau in neurons. The extensive work on tau in neurons has considerably advanced our understanding of how tau promotes either health or disease. Because OLGs are crucial to neuronal health at any age, an understanding of the functions and regulation of tau in OLGs could uncover new therapeutics for selective CNS neurodegenerative diseases.
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Affiliation(s)
- Patrizia LoPresti
- Department of Psychology, University of Illinois at Chicago, 1007 West Harrison Street, Chicago, IL 60607, USA.
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11
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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: 2.3] [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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12
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Belloli S, Zanotti L, Murtaj V, Mazzon C, Di Grigoli G, Monterisi C, Masiello V, Iaccarino L, Cappelli A, Poliani PL, Politi LS, Moresco RM. 18F-VC701-PET and MRI in the in vivo neuroinflammation assessment of a mouse model of multiple sclerosis. J Neuroinflammation 2018; 15:33. [PMID: 29402285 PMCID: PMC5800080 DOI: 10.1186/s12974-017-1044-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 12/15/2017] [Indexed: 11/17/2022] Open
Abstract
Background Positron emission tomography (PET) using translocator protein (TSPO) ligands has been used to detect neuroinflammatory processes in neurological disorders, including multiple sclerosis (MS). The aim of this study was to evaluate neuroinflammation in a mouse MS model (EAE) using TSPO-PET with 18F-VC701, in combination with magnetic resonance imaging (MRI). Methods MOG35-55/CFA and pertussis toxin protocol was used to induce EAE in C57BL/6 mice. Disease progression was monitored daily, whereas MRI evaluation was performed at 1, 2, and 4 weeks post-induction. Microglia activation was assessed in vivo by 18F-VC701 PET at the time of maximum disease score and validated by radioligand ex vivo distribution and immunohistochemistry at 2 and 4 weeks post-immunization. Results In vivo and ex vivo analyses show that 18F-VC701 significantly accumulates within the central nervous system (CNS), particularly in the cortex, striatum, hippocampus, cerebellum, and cervical spinal cord of EAE compared to control mice, at 2 weeks post-immunization. MRI confirmed the presence of focal brain lesions at 2 weeks post-immunization in both T1-weighted and T2 images. Of note, MRI abnormalities attenuated in later post-immunization phase. Neuropathological analysis confirmed the presence of microglial activation in EAE mice, consistent with the in vivo increase of 18F-VC701 uptake. Conclusion Increase of 18F-VC701 uptake in EAE mice is strongly associated with the presence of microglia activation in the acute phase of the disease. The combined use of TSPO-PET and MRI provided complementary evidence on the ongoing disease process, thus representing an attractive new tool to investigate neuronal damage and neuroinflammation at preclinical levels. Electronic supplementary material The online version of this article (10.1186/s12974-017-1044-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sara Belloli
- IBFM-CNR, Segrate, Italy.,Experimental Imaging Center, IRCCS San Raffaele Scientific Institute, Milan, Italy.,Milan Center for Neuroscience (NeuroMI) University of Milano-Bicocca, Milan, Italy
| | - Lucia Zanotti
- Unit of Immunogenetics, Leukemia Genomics and Immunobiology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Valentina Murtaj
- Experimental Imaging Center, IRCCS San Raffaele Scientific Institute, Milan, Italy.,PhD Program in Neuroscience, University of Milan-Bicocca, Monza, Italy.,Department of Medicine and Surgery, University of Milano-Bicocca, Via Cadore 48, Monza, 20900, Italy
| | - Cristina Mazzon
- Humanitas Clinical and Research Centre, Rozzano, Italy.,Biomedical Sciences Department, University of Padua, Padua, Italy
| | - Giuseppe Di Grigoli
- IBFM-CNR, Segrate, Italy.,Experimental Imaging Center, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Cristina Monterisi
- Department of Medicine and Surgery, University of Milano-Bicocca, Via Cadore 48, Monza, 20900, Italy
| | - Valeria Masiello
- Department of Medicine and Surgery, University of Milano-Bicocca, Via Cadore 48, Monza, 20900, Italy
| | - Leonardo Iaccarino
- Vita-Salute San Raffaele University and In Vivo Human Molecular and Structural Neuroimaging Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Andrea Cappelli
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, Siena, Italy
| | - Pietro Luigi Poliani
- Department of Molecular and Translational Medicine, Pathology Unit, University of Brescia, Brescia, Italy
| | - Letterio Salvatore Politi
- Experimental Imaging Center, IRCCS San Raffaele Scientific Institute, Milan, Italy.,Advanced MRI Center, University of Massachusetts Medical School, Worcester, MA, USA.,Neuroimaging Research, Boston Children's Hospital, Boston, MA, USA
| | - Rosa Maria Moresco
- IBFM-CNR, Segrate, Italy. .,Experimental Imaging Center, IRCCS San Raffaele Scientific Institute, Milan, Italy. .,Department of Medicine and Surgery, University of Milano-Bicocca, Via Cadore 48, Monza, 20900, Italy.
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13
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Sun J, Zhou H, Bai F, Ren Q, Zhang Z. Myelin injury induces axonal transport impairment but not AD-like pathology in the hippocampus of cuprizone-fed mice. Oncotarget 2017; 7:30003-17. [PMID: 27129150 PMCID: PMC5058659 DOI: 10.18632/oncotarget.8981] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Accepted: 04/16/2016] [Indexed: 12/02/2022] Open
Abstract
Both multiple sclerosis (MS) and Alzheimer's disease (AD) are progressive neurological disorders with myelin injury and memory impairment. However, whether myelin impairment could cause AD-like neurological pathology remains unclear. To explore neurological pathology following myelin injury, we assessed cognitive function, the expression of myelin proteins, axonal transport-associated proteins, axonal structural proteins, synapse-associated proteins, tau and beta amyloid and the status of neurons, using the cuprizone mouse model of demyelination. We found the mild impairment of learning ability in cuprizone-fed mice and the decreased expression of myelin basic protein (MBP) in the hippocampus. And anti-LINGO-1 improved learning ability and partly restored MBP level. Furthermore, we also found kinesin light chain (KLC), neurofilament light chain (NFL) and neurofilament heavy chain (NF200) were declined in demyelinated hippocampus, which could be partly improved by treatment with anti-LINGO-1. However, we did not observe the increased expression of beta amyloid, hyperphosphorylation of tau and loss of neurons in demyelinated hippocampus. Our results suggest that demyelination might lead to the impairment of neuronal transport, but not cause increased level of hyperphosphorylated tau and beta amyloid. Our research demonstrates remyelination might be an effective pathway to recover the function of neuronal axons and cognition in MS.
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Affiliation(s)
- Junjun Sun
- Department of Neuropsychiatry, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, China
| | - Hong Zhou
- Department of Neuropsychiatry, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, China
| | - Feng Bai
- Department of Neuropsychiatry, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, China
| | - Qingguo Ren
- Department of Neuropsychiatry, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, China
| | - Zhijun Zhang
- Department of Neuropsychiatry, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, China
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14
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Yin Z, Valkenburg F, Hornix BE, Mantingh-Otter I, Zhou X, Mari M, Reggiori F, Van Dam D, Eggen BJ, De Deyn PP, Boddeke E. Progressive Motor Deficit is Mediated by the Denervation of Neuromuscular Junctions and Axonal Degeneration in Transgenic Mice Expressing Mutant (P301S) Tau Protein. J Alzheimers Dis 2017; 60:S41-S57. [DOI: 10.3233/jad-161206] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Zhuoran Yin
- Department of Neuroscience, Section Medical Physiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- Department of Medical Ultrasound, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Femke Valkenburg
- Laboratory of Neurochemistry and Behavior, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | - Betty E. Hornix
- Department of Neurobiology, Groningen Institute for Evolutionary Life Science, University of Groningen, Groningen, The Netherlands
| | - Ietje Mantingh-Otter
- Department of Neuroscience, Section Medical Physiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Xingdong Zhou
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northeast Agricultural University, Harbin, China
| | - Muriel Mari
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Fulvio Reggiori
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Debby Van Dam
- Laboratory of Neurochemistry and Behavior, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
- Department of Neurology and Alzheimer Research Center, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Bart J.L. Eggen
- Department of Neuroscience, Section Medical Physiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Peter P. De Deyn
- Laboratory of Neurochemistry and Behavior, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
- Department of Neurology and Alzheimer Research Center, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- Biobank, Institute Born-Bunge, Antwerp, Belgium
| | - Erik Boddeke
- Department of Neuroscience, Section Medical Physiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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15
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Rubin K, Glazer S. The pertussis hypothesis: Bordetella pertussis colonization in the pathogenesis of Alzheimer’s disease. Immunobiology 2017; 222:228-240. [DOI: 10.1016/j.imbio.2016.09.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Accepted: 09/26/2016] [Indexed: 12/31/2022]
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16
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Alizadeh-Ghodsi M, Zavvari A, Ebrahimi-Kalan A, Shiri-Shahsavar MR, Yousefi B. The hypothetical roles of arsenic in multiple sclerosis by induction of inflammation and aggregation of tau protein: A commentary. Nutr Neurosci 2016; 21:92-96. [PMID: 27697018 DOI: 10.1080/1028415x.2016.1239399] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Multiple sclerosis (MS) is a disease which manifests demyelination of neuronal cells in the brain. Despite extensive research on the mechanisms of disease development and progression, the exact mechanism is not elucidated yet, which has hampered drug development and subsequent treatment of the disease. We have recently shown that the serum levels of arsenic and malondialdehyde, a lipid peroxidation marker, are high in MS patients. In this article, we would like to formulate the hypothesis that arsenic may cause MS by induction of inflammation, degeneration, and apoptosis in neuronal cells. The induction of ROS generation in cells upon exposure to arsenic as a heavy metal may be involved in the pathogenesis of MS. Tau protein, a member of the family of microtubule-associated proteins, is mainly expressed in neurons and contribute to the assembly of neuronal microtubules network. Arsenic may affect the hyperphosphorylation and aggregation of tau proteins and may be involved in the cascade leading to deregulation of tau function associated with neurodegeneration. For validation of this hypothesis, studies might be conducted to evaluate the association of arsenic levels and tau protein levels in MS patients. Further studies might also focus on the trafficking along microtubules in neurons of MS patient with regard to hyperphosphorylation of tau protein. This hypothesis may add a new dimension to the understanding of MS etiology and help to design novel therapeutic agents against potential targets that might be discovered. If this hypothesis proves to be true, tau phosphorylation inhibitors can be potential candidates for MS drug development.
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Affiliation(s)
- Mohammadreza Alizadeh-Ghodsi
- a Neurosciences Research Center , Tabriz University of Medical Sciences , Tabriz , Iran.,b Department of Biochemistry and Clinical Laboratories, Faculty of Medicine , Tabriz University of Medical Sciences , Tabriz , Iran
| | - Ali Zavvari
- b Department of Biochemistry and Clinical Laboratories, Faculty of Medicine , Tabriz University of Medical Sciences , Tabriz , Iran.,c Immunology Research Center , Tabriz University of Medical Sciences , Tabriz , Iran
| | - Abbas Ebrahimi-Kalan
- a Neurosciences Research Center , Tabriz University of Medical Sciences , Tabriz , Iran.,d Neurosciences Department, School of Advanced Medical Sciences , Tabriz University of Medical Sciences, Tabriz , Iran
| | - Mohammad Reza Shiri-Shahsavar
- e Department of Cellular and Molecular Nutrition, School of Nutritional Sciences and Dietetics, International Campus , Tehran University of Medical Sciences , Tehran , Iran
| | - Bahman Yousefi
- c Immunology Research Center , Tabriz University of Medical Sciences , Tabriz , Iran.,f Students' Research Committee , Tabriz University of Medical Sciences , Tabriz , Iran
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Inducible Expression of a Truncated Form of Tau in Oligodendrocytes Elicits Gait Abnormalities and a Decrease in Myelin: Implications for Selective CNS Degenerative Diseases. Neurochem Res 2015; 40:2188-99. [DOI: 10.1007/s11064-015-1707-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 08/14/2015] [Accepted: 08/19/2015] [Indexed: 12/25/2022]
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18
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Marciani DJ. Alzheimer's disease vaccine development: A new strategy focusing on immune modulation. J Neuroimmunol 2015; 287:54-63. [PMID: 26439962 DOI: 10.1016/j.jneuroim.2015.08.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Revised: 08/05/2015] [Accepted: 08/06/2015] [Indexed: 12/31/2022]
Abstract
Despite significant advances in the development of Alzheimer's disease (AD) vaccines effective in animal models, these prototypes have been clinically unsuccessful; apparently the result of using immunogens modified to prevent inflammation. Hence, a new paradigm is needed that uses entire AD-associated immunogens, a notion supported by recent successful passive immunotherapy results, with adjuvants that induce Th2-only while inhibiting without abrogating Th1 immunity. Here, we discuss the obstacles to AD vaccine development and Th2-adjuvants that by acting on dendritic and T cells, would elicit regardless of the antigen a safe and effective antibody response, while preventing damaging neuroinflammation and ameliorating immunosenescence.
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Affiliation(s)
- Dante J Marciani
- Qantu Therapeutics, Inc., 612 E. Main Street, Lewisville, TX 75057, USA.
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19
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Praet J, Guglielmetti C, Berneman Z, Van der Linden A, Ponsaerts P. Cellular and molecular neuropathology of the cuprizone mouse model: clinical relevance for multiple sclerosis. Neurosci Biobehav Rev 2015; 47:485-505. [PMID: 25445182 DOI: 10.1016/j.neubiorev.2014.10.004] [Citation(s) in RCA: 278] [Impact Index Per Article: 30.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 09/18/2014] [Accepted: 10/01/2014] [Indexed: 01/30/2023]
Abstract
The cuprizone mouse model allows the investigation of the complex molecular mechanisms behind nonautoimmune-mediated demyelination and spontaneous remyelination. While it is generally accepted that oligodendrocytes are specifically vulnerable to cuprizone intoxication due to their high metabolic demands, a comprehensive overview of the etiology of cuprizone-induced pathology is still missing to date. In this review we extensively describe the physico-chemical mode of action of cuprizone and discuss the molecular and enzymatic mechanisms by which cuprizone induces metabolic stress, oligodendrocyte apoptosis, myelin degeneration and eventually axonal and neuronal pathology. In addition, we describe the dual effector function of the immune system which tightly controls demyelination by effective induction of oligodendrocyte apoptosis, but in contrast also paves the way for fast and efficient remyelination by the secretion of neurotrophic factors and the clearance of cellular and myelinic debris. Finally, we discuss the many clinical symptoms that can be observed following cuprizone treatment, and how these strengthened the cuprizone model as a useful tool to study human multiple sclerosis, schizophrenia and epilepsy.
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20
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Effects of repeated intrathecal triamcinolone-acetonide application on cerebrospinal fluid biomarkers of axonal damage and glial activity in multiple sclerosis patients. Mol Diagn Ther 2015; 18:631-7. [PMID: 24986188 PMCID: PMC4245486 DOI: 10.1007/s40291-014-0114-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Background and Objectives Multiple sclerosis (MS) is the most common inflammatory disease of the central nervous system in young adults. Over time, the disease progresses and, with accumulating disability, symptoms such as spasticity may occur. Although several treatment options are available, some patients may not respond to first-line therapeutics. However, some of these patients may benefit from intrathecally administered triamcinolone-acetonide (TCA), a derivative of glucocorticosteroids (GCS). GCS may have neurotoxic effects, and cell apoptosis may occur. The aim of this study was to investigate the effects of TCA on biomarkers in the cerebrospinal fluid (CSF) suggestive of neurodegeneration. Methods In order to assess neurotoxic effects of TCA, neurofilament heavy-chain (NfH)SMI35, tau protein, and S-100B protein levels were determined before and during treatment with TCA in 54 patients with primary progressive MS, as well as relapsing MS (relapsing–remitting and secondary progressive MS). Results NfHSMI35 levels in the CSF of patients treated with TCA intrathecally did not increase significantly during the treatment cycle (p = 0.068). After application of TCA, tau protein levels were increased significantly at day 4 (p = 0.03) and at day 8 (p ≤ 0.001). S-100B protein levels decreased significantly (p ≤ 0.05) during treatment with TCA. Conclusion NfHSMI35 levels did not change significantly; however, tau protein levels did increase significantly within the reference range. Taking these findings together, the long-term effects of TCA on NfHSMI35 and tau protein levels need to be investigated further to understand whether levels of both biomarkers will change over repeated TCA applications. Interestingly, S-100B protein levels decreased significantly during the first applications, which may have represented reduced astrocytic activity during TCA treatment.
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21
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Abstract
Supplemental digital content is available in the text. Understanding the pathophysiologic mechanisms underlying Alzheimer disease relies on knowledge of disease onset and the sequence of development of brain pathologies. We present a comprehensive analysis of early and progressive changes in a mouse model that demonstrates a full spectrum of characteristic Alzheimer disease–like pathologies. This model demonstrates an altered immune redox state reminiscent of the human disease and capitalizes on data indicating critical differences between human and mouse immune responses, particularly in nitric oxide levels produced by immune activation of the NOS2 gene. Using the APPSwDI+/+/mNos2−/− (CVN-AD) mouse strain, we show a sequence of pathologic events leading to neurodegeneration,which include pathologically hyperphosphorylated tau in the perforant pathway at 6 weeks of age progressing to insoluble tau, early appearance of β-amyloid peptides in perivascular deposits around blood vessels in brain regions known to be vulnerable to Alzheimer disease, and progression to damage and overt loss in select vulnerable neuronal populations in these regions. The role of species differences between hNOS2 and mNos2 was supported by generating mice in which the human NOS2 gene replaced mNos2. When crossed with CVN-AD mice, pathologic characteristics of this new strain (APPSwDI+/−/HuNOS2tg+/+/mNos2−/−) mimicked the pathologic phenotypes found in the CVN-AD strain.
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22
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Shinohara M, Sato N, Shimamura M, Kurinami H, Hamasaki T, Chatterjee A, Rakugi H, Morishita R. Possible modification of Alzheimer's disease by statins in midlife: interactions with genetic and non-genetic risk factors. Front Aging Neurosci 2014; 6:71. [PMID: 24795626 PMCID: PMC4005936 DOI: 10.3389/fnagi.2014.00071] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Accepted: 03/30/2014] [Indexed: 12/28/2022] Open
Abstract
The benefits of statins, commonly prescribed for hypercholesterolemia, in treating Alzheimer's disease (AD) have not yet been fully established. A recent randomized clinical trial did not show any therapeutic effects of two statins on cognitive function in AD. Interestingly, however, the results of the Rotterdam study, one of the largest prospective cohort studies, showed reduced risk of AD in statin users. Based on the current understanding of statin actions and AD pathogenesis, it is still worth exploring whether statins can prevent AD when administered decades before the onset of AD or from midlife. This review discusses the possible beneficial effects of statins, drawn from previous clinical observations, pathogenic mechanisms, which include β-amyloid (Aβ) and tau metabolism, genetic and non-genetic risk factors (apolipoprotein E, cholesterol, sex, hypertension, and diabetes), and other clinical features (vascular dysfunction and oxidative and inflammatory stress) of AD. These findings suggest that administration of statins in midlife might prevent AD in late life by modifying genetic and non-genetic risk factors for AD. It should be clarified whether statins inhibit Aβ accumulation, tau pathological features, and brain atrophy in humans. To answer this question, a randomized controlled study using amyloid positron emission tomography (PET), tau-PET, and magnetic resonance imaging would be useful. This clinical evaluation could help us to overcome this devastating disease.
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Affiliation(s)
- Mitsuru Shinohara
- Department of Clinical Gene Therapy, Graduate School of Medicine, Osaka UniversitySuita, Japan
- Department of Geriatric Medicine, Graduate School of Medicine, Osaka UniversitySuita, Japan
| | - Naoyuki Sato
- Department of Clinical Gene Therapy, Graduate School of Medicine, Osaka UniversitySuita, Japan
- Department of Geriatric Medicine, Graduate School of Medicine, Osaka UniversitySuita, Japan
| | - Munehisa Shimamura
- Division of Vascular Medicine and Epigenetics, Department of Child Development, United Graduate School of Child Development, Osaka University Office for University-Industry CollaborationSuita, Japan
| | - Hitomi Kurinami
- Division of Vascular Medicine and Epigenetics, Department of Child Development, United Graduate School of Child Development, Osaka University Office for University-Industry CollaborationSuita, Japan
| | - Toshimitsu Hamasaki
- Department of Biomedical Statistics, Graduate School of Medicine, Osaka UniversitySuita, Japan
| | - Amarnath Chatterjee
- Department of Clinical Gene Therapy, Graduate School of Medicine, Osaka UniversitySuita, Japan
| | - Hiromi Rakugi
- Department of Geriatric Medicine, Graduate School of Medicine, Osaka UniversitySuita, Japan
| | - Ryuichi Morishita
- Department of Clinical Gene Therapy, Graduate School of Medicine, Osaka UniversitySuita, Japan
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23
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Astragaloside IV attenuates experimental autoimmune encephalomyelitis of mice by counteracting oxidative stress at multiple levels. PLoS One 2013; 8:e76495. [PMID: 24124567 PMCID: PMC3790693 DOI: 10.1371/journal.pone.0076495] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Accepted: 08/29/2013] [Indexed: 12/04/2022] Open
Abstract
Multiple sclerosis (MS) is a chronic autoimmune neuroinflammatory disease found mostly in young adults in the western world. Oxidative stress induced neuronal apoptosis plays an important role in the pathogenesis of MS. In current study, astragaloside IV (ASI), a natural saponin molecule isolated from Astragalus membranceus, given at 20 mg/kg daily attenuated the severity of experimental autoimmune encephalomyelitis (EAE) in mice significantly. Further studies disclosed that ASI treatment inhibited the increase of ROS and pro-inflammatory cytokine levels, down-regulation of SOD and GSH-Px activities, and elevation of iNOS, p53 and phosphorylated tau in central nervous system (CNS) as well as the leakage of BBB of EAE mice. Meanwhile, the decreased ratio of Bcl-2/Bax was reversed by ASI. Moreover, ASI regulated T-cell differentiation and infiltration into CNS. In neuroblast SH-SY5Y cells, ASI dose-dependently reduced cellular ROS level and phosphorylation of tau in response to hydrogen peroxide challenge by modulation of Bcl-2/Bax ratio. ASI also inhibited activation of microglia both in vivo and in vitro. iNOS up-regulation induced by IFNγ stimulation was abolished by ASI dose-dependently in BV-2 cells. In summary, ASI prevented the severity of EAE progression possibly by counterbalancing oxidative stress and its effects via reduction of cellular ROS level, enhancement of antioxidant defense system, increase of anti-apoptotic and anti-inflammatory pathways, as well as modulation of T-cell differentiation and infiltration into CNS. The study suggested ASI may be effective for clinical therapy/prevention of MS.
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24
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Szalardy L, Zadori D, Simu M, Bencsik K, Vecsei L, Klivenyi P. Evaluating biomarkers of neuronal degeneration and neuroinflammation in CSF of patients with multiple sclerosis–osteopontin as a potential marker of clinical severity. J Neurol Sci 2013; 331:38-42. [DOI: 10.1016/j.jns.2013.04.024] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 03/31/2013] [Accepted: 04/22/2013] [Indexed: 01/26/2023]
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25
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Agúndez JAG, García-Martín E, Martínez C, Benito-León J, Millán-Pascual J, Calleja P, Díaz-Sánchez M, Pisa D, Turpín-Fenoll L, Alonso-Navarro H, Ayuso-Peralta L, Torrecillas D, Plaza-Nieto JF, Jiménez-Jiménez FJ. MAPT gene rs1052553 variant is not associated with the risk for multiple sclerosis. Hum Immunol 2013; 74:1705-8. [PMID: 23911736 DOI: 10.1016/j.humimm.2013.07.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Revised: 07/08/2013] [Accepted: 07/19/2013] [Indexed: 02/08/2023]
Abstract
BACKGROUND/OBJECTIVES Some experimental data suggest a possible role of tau protein in the pathogenesis of multiple sclerosis (MS) and in experimental autoimmune encephalomyelitis. The aim of this study was to investigate a possible influence of the SNP rs1052553 in the MAPT gene in the risk for relapsing bout onset (relapsing-remitting and secondary progressive) MS. METHODS We analyzed the allelic and genotype frequency of MAPT rs1052553, which has been associated with some neurodegenerative diseases, in 259 patients with relapsing bout onset MS and 291 healthy controls, using TaqMan Assays. RESULTS MAPT rs1052553 allelic and genotype frequencies did not differ significantly between relapsing bout onset MS patients and controls, and were unrelated with the age of onset of MS or gender. CONCLUSIONS These results suggest that MAPT rs1052553 polymorphism is not related with the risk for relapsing bout onset MS.
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Affiliation(s)
- José A G Agúndez
- Department of Pharmacology, University of Extremadura, Cáceres, Spain
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26
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Lymphocytes with cytotoxic activity induce rapid microtubule axonal destabilization independently and before signs of neuronal death. ASN Neuro 2013; 5:e00105. [PMID: 23289514 PMCID: PMC3565378 DOI: 10.1042/an20120087] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
MS (multiple sclerosis) is the most prevalent autoimmune disease of the CNS (central nervous system) historically characterized as an inflammatory and demyelinating disease. More recently, extensive neuronal pathology has lead to its classification as a neurodegenerative disease as well. While the immune system initiates the autoimmune response it remains unclear how it orchestrates neuronal damage. In our previous studies, using in vitro cultured embryonic neurons, we demonstrated that MBP (myelin basic protein)-specific encephalitogenic CD4 T-cells induce early neuronal damage. In an extension of those studies, here we show that polarized CD4 Th1 and Th17 cells as wells as CD8 T-cells and NK (natural killer) cells induce microtubule destabilization within neurites in a contact-independent manner. Owing to the cytotoxic potential of these immune cells, we isolated the luminal components of lytic granules and determined that they were sufficient to drive microtubule destabilization. Since lytic granules contain cytolytic proteins, we determined that the induction of microtubule destabilization occurred prior to signs of apoptosis. Furthermore, we determined that microtubule destabilization was largely restricted to axons, sparing dendrites. This study demonstrated that lymphocytes with cytolytic activity have the capacity to directly drive MAD (microtubule axonal destabilization) in a bystander manner that is independent of neuronal death.
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27
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Mice devoid of Tau have increased susceptibility to neuronal damage in myelin oligodendrocyte glycoprotein-induced experimental autoimmune encephalomyelitis. J Neuropathol Exp Neurol 2012; 71:422-33. [PMID: 22487860 DOI: 10.1097/nen.0b013e3182540d2e] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The abundant axonal microtubule-associated protein tau regulates microtubule and actin dynamics, thereby contributing to normal neuronal function. We examined whether mice deficient in tau (Tau(-/-)) or with high levels of human tau differ from wild-type (WT) mice in their susceptibility to neuroaxonal injury in experimental autoimmune encephalomyelitis, an animal model of multiple sclerosis. After sensitization with MOG35-55, there was no difference in clinical disease course between human tau and WT mice, but Tau mice had more severe clinical disease and significantly more axonal damage in spinal cord white matter than those in WT mice. Axonal damage in gray matter correlated with clinical severity in individual mice. By immunoblot analysis, the early microtubule-associated protein-1b was increased 2-fold in the spinal cords of Tau mice with chronic experimental autoimmune encephalomyelitis versus naive Tau mice. This difference was not detected in comparable WT animals, which suggests that there was compensation for the loss of tau in the deficient mice. In addition, levels of the growth arrest-specific protein 7b, a tau-binding protein that is stabilized when bound to tau, were higher in WT than those in Tau(-/-) spinal cord samples. These data indicate that loss of tau exacerbates experimental autoimmune encephalomyelitis and suggest that maintaining tau integrity might reduce the axonal damage that occurs in inflammatory neurodegenerative diseases such as multiple sclerosis.
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28
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Petzold A, Tozer DJ, Schmierer K. Axonal damage in the making: neurofilament phosphorylation, proton mobility and magnetisation transfer in multiple sclerosis normal appearing white matter. Exp Neurol 2011; 232:234-9. [PMID: 21958956 PMCID: PMC3277890 DOI: 10.1016/j.expneurol.2011.09.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Revised: 09/06/2011] [Accepted: 09/09/2011] [Indexed: 11/29/2022]
Abstract
Aims Multiple sclerosis (MS) leaves a signature on the phosphorylation and thus proton binding capacity of axonal neurofilament (Nf) proteins. The proton binding capacity in a tissue is the major determinant for exchange between bound and free protons and thus the magnetisation transfer ratio (MTR). This study investigated whether the MTR of non-lesional white matter (NLWM) was related to the brain tissue concentration of neurofilament phosphoforms. Methods Unfixed post-mortem brain slices of 12 MS patients were analysed using MTR, T1 at 1.5 T. Blocks containing NLWM were processed for embedding in paraffin and inspected microscopically. Adjacent tissue was microdissected, homogenised and specific protein levels were quantified by ELISA for the Nf heavy chain (NfH) phosphoforms, glial fibrillary acidic protein (GFAP), S100B and ferritin. Results Averaged hyperphosphorylated NfH (SMI34) but not phosphorylated NfH (SMI35) levels were different between individual patients NLWM. The concentration of hyperphosphorylated NfH-SMI34 correlated with T1 (R = 0.70, p = 0.0114) and — inversely — with MTR (R =−0.73, p = 0.0065). NfH-SMI35 was not correlated to any of the MR indices. Conclusions Post-translational modifications of axonal proteins such as phosphorylation of neurofilaments occur in NLWM and may precede demyelination. The resulting change of proton mobility influences MTR and T1. This permits the in vivo detection of these subtle tissue changes on a proteomic level in patients with MS.
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Affiliation(s)
- A Petzold
- UCL Institute of Neurology, Department of Neuroinflammation, Queen Square, London WC1N 3BG, UK.
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Multiple sclerosis as a neurodegenerative disease: pathology, mechanisms and therapeutic implications. Curr Opin Neurol 2011; 24:224-9. [PMID: 21455066 DOI: 10.1097/wco.0b013e328346056f] [Citation(s) in RCA: 120] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
PURPOSE OF REVIEW Multiple sclerosis (MS) treatments targeting the inflammatory nature of the disease have become increasingly effective in recent years. However, our efforts at targeting the progressive disease phase have so far been largely unsuccessful. This has led to the hypothesis that disease mechanisms independent of an adaptive immune response contribute to disease progression and closely resemble neurodegeneration. RECENT FINDINGS Nonfocal, diffuse changes in the MS brain, especially axonal loss and mitochondrial dysfunction, prove better correlates of disability than total lesion load and have been associated with disease progression. Molecular changes in nondemyelinated MS tissue also suggest that alterations in the MS brain are widespread and consist of pro-inflammatory as well as anti-inflammatory responses. However, local lymphocytic inflammation and microglial activation are salient features of the chronic disease, and T-cell-mediated inflammation contributes to tissue damage. In addition, neuroaxonal cytoskeletal alterations have been associated with disease progression. SUMMARY Our knowledge of the molecular mechanisms leading to neuroaxonal damage and demise in MS is steadily increasing. Experimental therapies targeting neuroaxonal ionic imbalances and energy metabolism in part show promising results. A better understanding of the molecular mechanisms underlying chronic progression will substantially aid the development of new treatment strategies.
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Fitzner D, Simons M. Chronic progressive multiple sclerosis - pathogenesis of neurodegeneration and therapeutic strategies. Curr Neuropharmacol 2011; 8:305-15. [PMID: 21358979 PMCID: PMC3001222 DOI: 10.2174/157015910792246218] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Revised: 04/08/2010] [Accepted: 04/08/2010] [Indexed: 11/22/2022] Open
Abstract
Multiple sclerosis (MS) is an inflammatory, autoimmune, demyelinating disease of the central nervous system (CNS) that usually starts as a relapsing-remitting disease. In most patients the disease evolves into a chronic progressive phase characterized by continuous accumulation of neurological deficits. While treatment of relapsing-remitting MS (RRMS) has improved dramatically over the last decade, the therapeutic options for chronic progressive MS, both primary and secondary, are still limited. In order to find new pharmacological targets for the treatment of chronic progressive MS, the mechanisms of the underlying neurodegenerative process that becomes apparent as the disease progresses need to be elucidated. New animal models with prominent and widespread progressive degenerative components of MS have to be established to study both inflammatory and non-inflammatory mechanisms of neurodegeneration. Here, we discuss disease mechanisms and treatment strategies for chronic progressive MS.
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Affiliation(s)
- Dirk Fitzner
- Max-Planck-Institute for Experimental Medicine, Hermann-Rein-Str. 3, Göttingen, Germany
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31
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Cerebrospinal fluid and blood biomarkers of neuroaxonal damage in multiple sclerosis. Mult Scler Int 2011; 2011:767083. [PMID: 22096642 PMCID: PMC3198600 DOI: 10.1155/2011/767083] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Accepted: 02/08/2011] [Indexed: 12/20/2022] Open
Abstract
Following emerging evidence that neurodegenerative processes in multiple sclerosis (MS) are present from its early stages, an intensive scientific interest has been directed to biomarkers of neuro-axonal damage in body fluids of MS patients. Recent research has introduced new candidate biomarkers but also elucidated pathogenetic and clinical relevance of the well-known ones. This paper reviews the existing data on blood and cerebrospinal fluid biomarkers of neuroaxonal damage in MS and highlights their relation to clinical parameters, as well as their potential predictive value to estimate future disease course, disability, and treatment response. Strategies for future research in this field are suggested.
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Laha JK, Zhang X, Qiao L, Liu M, Chatterjee S, Robinson S, Kosik KS, Cuny GD. Structure-activity relationship study of 2,4-diaminothiazoles as Cdk5/p25 kinase inhibitors. Bioorg Med Chem Lett 2011; 21:2098-101. [PMID: 21353545 DOI: 10.1016/j.bmcl.2011.01.140] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Revised: 01/27/2011] [Accepted: 01/31/2011] [Indexed: 11/30/2022]
Abstract
Cdk5/p25 has emerged as a principle therapeutic target for numerous acute and chronic neurodegenerative diseases, including Alzheimer's disease. A structure-activity relationship study of 2,4-diaminothiazole inhibitors revealed that increased Cdk5/p25 inhibitory activity could be accomplished by incorporating pyridines on the 2-amino group and addition of substituents to the 2- or 3-position of the phenyl ketone moiety. Interpretation of the SAR results for many of the analogs was aided through in silico docking with Cdk5/p25 and calculating protein hydrations sites using WaterMap. Finally, improved in vitro mouse microsomal stability was also achieved.
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Affiliation(s)
- Joydev K Laha
- Laboratory for Drug Discovery in Neurodegeneration, Harvard NeuroDiscovery Center, Brigham & Women's Hospital and Harvard Medical School, 65 Landsdowne Street, Cambridge, MA 02139, USA
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Pareek TK, Lam E, Zheng X, Askew D, Kulkarni AB, Chance MR, Huang AY, Cooke KR, Letterio JJ. Cyclin-dependent kinase 5 activity is required for T cell activation and induction of experimental autoimmune encephalomyelitis. ACTA ACUST UNITED AC 2010; 207:2507-19. [PMID: 20937706 PMCID: PMC2964575 DOI: 10.1084/jem.20100876] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Cyclin-dependent kinase 5 (Cdk5) is a ubiquitously expressed serine/threonine kinase. However, a requirement for Cdk5 has been demonstrated only in postmitotic neurons where there is abundant expression of its activating partners p35 and/or p39. Although hyperactivation of the Cdk5-p35 complex has been found in a variety of inflammatory neurodegenerative disorders, the potential contribution of nonneuronal Cdk5-p35 activity has not been explored in this context. We describe a previously unknown function of the Cdk5-p35 complex in T cells that is required for induction of experimental autoimmune encephalomyelitis (EAE). T cell receptor (TCR) stimulation leads to a rapid induction of Cdk5-p35 expression that is required for T lymphocyte activation. Chimeric mice lacking Cdk5 gene expression in hematopoietic tissues (Cdk5(-/-C)) are resistant to induction of EAE, and adoptive transfer of either Cdk5(-/-C) or p35(-/-) encephalitogenic lymphocytes fails to transfer disease. Moreover, our data reveal a novel mechanism involving Cdk5-mediated phosphorylation of the actin modulator coronin 1a on threonine 418. Cdk5-deficient lymphocytes lack this posttranslational modification of coronin 1a and exhibit defective TCR-induced actin polarization and reduced migration toward CCL-19. These data define a distinct role for Cdk5 in lymphocyte biology and suggest that inhibition of this kinase may be beneficial in the treatment of T cell-mediated inflammatory disorders.
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Affiliation(s)
- Tej K Pareek
- Division of Pediatric Hematology/Oncology, Department of Pediatrics, University Hospitals Case Medical Center and The Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106, USA
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Larionov S, Wielgat P, Wang Y, Thal DR, Neumann H. Spatially pathogenic forms of tau detected in Alzheimer's disease brain tissue by fluorescence lifetime-based Förster resonance energy transfer. J Neurosci Methods 2010; 192:127-37. [PMID: 20655329 DOI: 10.1016/j.jneumeth.2010.07.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Revised: 07/15/2010] [Accepted: 07/16/2010] [Indexed: 01/07/2023]
Abstract
In tauopathies including Alzheimer's disease (AD) tau molecules have lost their normal spatial distance to each other and appear in oligomeric or aggregated forms. Conventional immunostaining methods allow detection of abnormally phosphorylated or conformationally altered aggregated tau proteins, but fail to visualize oligomeric forms of tau. Here we show that tau molecules that lost their normal spatial localization can be detected on a subcellular level in postmortem central nervous system (CNS) tissue sections of AD patients by fluorescence lifetime-based Förster resonance energy transfer (FRET). Paraffin sections were co-immunostained with two tau-specific monoclonal antibodies recognizing the same epitope, but labeled with distinct fluorescence dyes suitable for spatial resolution at a nanometer scale by lifetime-based FRET. A FRET signal was detected in neuritic plaques and neurofibrillary tangles of CNS tissue sections of AD patients, showing associated tau proteins typically reflecting either fibrillary, oligomeric or aggregated tau. The 'pretangle-like' structures within the neuronal perikarya did not contain spatially pathogenic forms of tau accordingly to this method. Data demonstrate that fluorescence lifetime-based FRET can be applied to human brain tissue sections to detect pathogenic forms of tau molecules that lost their normal spatial distance.
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Affiliation(s)
- Sergey Larionov
- Neural Regeneration Unit, Institute of Reconstructive Neurobiology, University Bonn and Hertie Foundation, University Bonn, Sigmund-Freud-Str. 25, 53105 Bonn, Germany
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35
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Stadelmann C, Wegner C, Brück W. Inflammation, demyelination, and degeneration - recent insights from MS pathology. Biochim Biophys Acta Mol Basis Dis 2010; 1812:275-82. [PMID: 20637864 DOI: 10.1016/j.bbadis.2010.07.007] [Citation(s) in RCA: 179] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Revised: 06/30/2010] [Accepted: 07/06/2010] [Indexed: 12/29/2022]
Abstract
Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system which responds to anti-inflammatory treatments in the early disease phase. However, the pathogenesis of the progressive disease phase is less well understood, and inflammatory as well as neurodegenerative mechanisms of tissue damage are currently being discussed. This review summarizes current knowledge on the interrelation between inflammation, demyelination, and neurodegeneration derived from the study of human autopsy and biopsy brain tissue and experimental models of MS.
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Tumani H, Hartung HP, Hemmer B, Teunissen C, Deisenhammer F, Giovannoni G, Zettl UK. Cerebrospinal fluid biomarkers in multiple sclerosis. Neurobiol Dis 2009; 35:117-27. [PMID: 19426803 DOI: 10.1016/j.nbd.2009.04.010] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2009] [Revised: 04/10/2009] [Accepted: 04/27/2009] [Indexed: 12/25/2022] Open
Abstract
In patients with multiple sclerosis (MS) intensive efforts are directed at identifying biomarkers in bodily fluids related to underlying disease mechanisms, disease activity and progression, and therapeutic response. Besides MR imaging parameters cerebrospinal fluid (CSF) biomarkers provide important and specific information since changes in the CSF composition may reflect disease mechanisms inherent to MS. The different cellular and protein-analytical methods of the CSF and the recommended standard of the diagnostic CSF profile in MS are described. A brief update on possible CSF biomarkers that might reflect key pathological processes of MS such as inflammation, demyelination, neuroaxonal loss, gliosis and regeneration is provided.
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Affiliation(s)
- Hayrettin Tumani
- Department of Neurology, University of Ulm, Oberer Eselsberg 45, Ulm D-89081, Germany.
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37
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Anderson JM, Patani R, Reynolds R, Nicholas R, Compston A, Spillantini MG, Chandran S. Evidence for abnormal tau phosphorylation in early aggressive multiple sclerosis. Acta Neuropathol 2009; 117:583-9. [PMID: 19288121 DOI: 10.1007/s00401-009-0515-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Revised: 03/04/2009] [Accepted: 03/05/2009] [Indexed: 11/25/2022]
Abstract
Although progression in multiple sclerosis is pathologically dominated by neurodegeneration, the underlying mechanism is unknown. Abnormal hyperphosphorylation of tau is implicated in the aetiopathogenesis of some common neurodegenerative disorders. We recently demonstrated the association of insoluble tau with established secondary progressive MS, raising the hypothesis that its accumulation is relevant to disease progression. In order to begin to determine the temporal emergence of abnormal tau with disease progression in MS, we examined tau phosphorylation in cerebral tissue from a rare case of early aggressive MS. We report tau hyperphosphorylation occurring in multiple cell types, with biochemical analysis confirming restriction to the soluble fraction. The absence of sarcosyl-insoluble tau fraction in early disease and its presence in secondary progression raises the possibility that insoluble tau accumulates with disease progression.
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Affiliation(s)
- Jane Marian Anderson
- Cambridge Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Forvie Site, Robinson Way, Cambridge, UK
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38
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Statins reduce the neurofibrillary tangle burden in a mouse model of tauopathy. J Neuropathol Exp Neurol 2009; 68:314-25. [PMID: 19225406 DOI: 10.1097/nen.0b013e31819ac3cb] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Statin treatment has been associated with a reduced risk of Alzheimer disease and decreased amyloid deposition in mouse models. No animal studies have reported effects of statins on tau aggregates and neurofibrillary tangles (NFTs), the pathological hallmarks of Alzheimer disease that correlate with dementia. We investigated the effect of statins on NFTs in a transgenic mouse tauopathy model and found the following: 1) 1-month treatment with the blood-brain barrier-permeable agent simvastatin in normocholesterolemic aged mice significantly reduced the NFT burden and decreased lectin-positive microglia; 2) simvastatin significantly decreased NFTs and improved T-maze performance in young animals treated for 8 months; 3) treatment of hypercholesterolemic mice for 5 months with blood-brain barrier-impermeable atorvastatin markedly reduced the NFT burden and decreased lectin-positive microglia; 4) nonstatin cholesterol-lowering strategies showed a modest NFT decrease compared with statin treatment; and 5) there was a positive correlation between microglial and NFT burden (r = 0.8). Together, these results suggest that statins reduce NFT burden irrespective of blood-brain barrier permeability at both early and late ages in long- and short-term treatment paradigms and under normocholesterolemic and hypercholesterolemic conditions. The decrease in microglia, coupled with the limited effect of nonstatin cholesterol lowering, suggests that the anti-NFT effect of statins may be related to their anti-inflammatory and not necessarily to their cholesterol-lowering properties. Statins may provide therapy against NFTs in tauopathies, particularly when NFTs are the major neuropathologic component.
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39
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Laporte V, Ait-Ghezala G, Volmar CH, Ganey C, Ganey N, Wood M, Mullan M. CD40 ligation mediates plaque-associated tau phosphorylation in β-amyloid overproducing mice. Brain Res 2008; 1231:132-42. [DOI: 10.1016/j.brainres.2008.06.032] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2007] [Revised: 05/30/2008] [Accepted: 06/01/2008] [Indexed: 12/30/2022]
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40
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Anderson JM, Hampton DW, Patani R, Pryce G, Crowther RA, Reynolds R, Franklin RJM, Giovannoni G, Compston DAS, Baker D, Spillantini MG, Chandran S. Abnormally phosphorylated tau is associated with neuronal and axonal loss in experimental autoimmune encephalomyelitis and multiple sclerosis. ACTA ACUST UNITED AC 2008; 131:1736-48. [PMID: 18567922 DOI: 10.1093/brain/awn119] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The pathological correlate of clinical disability and progression in multiple sclerosis is neuronal and axonal loss; however, the underlying mechanisms are unknown. Abnormal phosphorylation of tau is a common feature of some neurodegenerative disorders, such as Alzheimer's disease. We investigated the presence of tau hyperphosphorylation and its relationship with neuronal and axonal loss in chronic experimental autoimmune encephalomyelitis (CEAE) and in brain samples from patients with secondary progressive multiple sclerosis. We report the novel finding of abnormal tau phosphorylation in CEAE. We further show that accumulation of insoluble tau is associated with both neuronal and axonal loss that correlates with progression from relapsing-remitting to chronic stages of EAE. Significantly, analysis of secondary progressive multiple sclerosis brain tissue also revealed abnormally phosphorylated tau and the formation of insoluble tau. Together, these observations provide the first evidence implicating abnormal tau in the neurodegenerative phase of tissue injury in experimental and human demyelinating disease.
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Affiliation(s)
- J M Anderson
- Department of Clinical Neurosciences, Cambridge Centre for Brain Repair, University of Cambridge, Forvie Site, Robinson Way, Cambridge, UK
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41
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Brown AM, Baucum AJ, Bass MA, Colbran RJ. Association of protein phosphatase 1 gamma 1 with spinophilin suppresses phosphatase activity in a Parkinson disease model. J Biol Chem 2008; 283:14286-94. [PMID: 18372251 PMCID: PMC2386916 DOI: 10.1074/jbc.m801377200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2008] [Revised: 03/26/2008] [Indexed: 11/06/2022] Open
Abstract
Sustained nigrostriatal dopamine depletion increases the serine/threonine phosphorylation of multiple striatal proteins that play a role in corticostriatal synaptic plasticity, including Thr(286) phosphorylation of calcium/calmodulin-dependent protein kinase IIalpha (CaMKIIalpha). Mechanisms underlying these changes are unclear, but protein phosphatases play a critical role in the acute modulation of striatal protein phosphorylation. Here we show that dopamine depletion for periods ranging from 3 weeks to 10 months significantly reduces the total activity of protein phosphatase (PP) 1, but not of PP2A, in whole lysates of rat striatum, as measured using multiple substrates, including Thr(286)-autophosphorylated CaMKIIalpha. Striatal PP1 activity is partially inhibited by a fragment of the PP1-binding protein neurabin-I, Nb-(146-493), because of the selective inhibition of the PP1gamma(1) isoform. The fraction of PP1 activity that is insensitive to Nb-(146-493) was unaffected by dopamine depletion, demonstrating that dopamine depletion specifically reduces the activity of PP1 isoforms that are sensitive to Nb-(146-493) (i.e. PP1gamma(1)). However, total striatal levels of PP1gamma(1) or any other PP1 isoform were unaffected by dopamine depletion, and our previous studies showed that total levels of the PP1 regulatory/targeting proteins DARPP-32, spinophilin, and neurabin were also unchanged. Rather, co-immunoprecipitation experiments demonstrated that dopamine depletion increases the association of PP1gamma(1) with spinophilin in striatal extracts. In combination, these data demonstrate that striatal dopamine depletion inhibits a specific synaptic phosphatase by increasing PP1gamma(1) interaction with spinophilin, perhaps contributing to hyperphosphorylation of synaptic proteins and disruptions of synaptic plasticity and/or dendritic morphology.
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Affiliation(s)
- Abigail M Brown
- Department of Molecular Physiology and Biophysics, Center for Molecular Neuroscience, Vanderbilt Kennedy Center for Research on Human Development, Vanderbilt University, Nashville, TN 37232, USA
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Chun W, Waldo GS, Johnson GVW. Split GFP complementation assay: a novel approach to quantitatively measure aggregation of tau in situ: effects of GSK3beta activation and caspase 3 cleavage. J Neurochem 2007; 103:2529-39. [PMID: 17908237 DOI: 10.1111/j.1471-4159.2007.04941.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
To quantitatively measure tau aggregation in situ, we established a cell model system using a split green fluorescence protein (GFP) complementation assay. In this assay the more aggregated the protein of interest the lower the GFP fluorescence. Tau microtubule-binding domain constructs, whose aggregation characteristics have been described previously (Khlistunova et al. 2006), were used to validate the assay. The aggregation-prone construct exhibited the lowest GFP intensity whereas the aggregation-resistant construct showed the highest GFP intensity. To examine the role of glycogen synthase kinase 3beta (GSK3beta) activity and caspase 3 cleavage on tau aggregation, GFP complementation of full length (T4), caspase-cleaved (T4C3), and pseudophosphorylated at S396/S404 (T4-2EC) tau was examined in the presence of an active or a kinase-dead GSK3beta. Extensive phosphorylation of T4 by GSK3beta resulted in increased GFP intensity. T4C3 showed neither efficient phosphorylation nor a significant GFP intensity change by GSK3beta. The GFP intensity of T4-2EC was significantly reduced by GSK3beta accompanying its presence in the sarkosyl-insoluble fraction, thus demonstrating that T4-2EC was partitioning into aggregates. This indicates that if the majority of tau is phosphorylated at S396/S404, in combination with increased GSK3beta activity, tau aggregation is favored. These data demonstrate that split GFP complementation may be a valuable approach to determine the aggregation process in living cells.
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Affiliation(s)
- Wanjoo Chun
- Department of Psychiatry, University of Alabama at Birmingham School of Medicine, Alabama, USA
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43
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Chun W, Johnson GVW. Activation of Glycogen Synthase Kinase 3β Promotes the Intermolecular Association of Tau. J Biol Chem 2007; 282:23410-7. [PMID: 17565981 DOI: 10.1074/jbc.m703706200] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Tau is hyperphosphorylated and undergoes proteolysis in Alzheimer disease brain. Caspase-cleaved tau efficiently forms fibrillary structures in vitro and in situ. Glycogen synthase kinase 3beta (GSK3beta) phosphorylates tau and induces the aggregation of caspase-cleaved tau in situ. Given the hypothesis that increased association of tau precedes the formation of fibrillar structures, we generated a cell model to quantitate the extent of tau association in situ using fluorescence resonance energy transfer (FRET) microscopy. The cyan and yellow fluorescent proteins were attached to full-length (T4) and caspase-cleaved (T4C3) tau at either the N or C termini, and a pair of cyan and yellow fluorescent protein-tagged tau were co-transfected into human embryonic kidney cells. The FRET efficiency was examined in the presence of a constitutively active or a kinase-dead GSK3beta. Active GSK3beta significantly increased FRET efficiency with both T4 and T4C3, indicating that GSK3beta activation resulted in an increase in the self-association of both T4 and T4C3, but interestingly only T4 is efficiently phosphorylated by GSK3beta. There was no significant difference in FRET efficiency between T4 and T4C3, although only T4C3 in the presence of active GSK3beta leads to the formation of Sarkosyl-insoluble inclusions. These FRET studies demonstrate that GSK3beta facilitates the association of T4 and T4C3, and the presence of caspase-cleaved tau is necessary for the evolution of tau oligomers into Sarkosyl-insoluble inclusions even though it is not extensively phosphorylated. These data imply that increased association of tau should not be regarded as a direct indicator of the formation of insoluble tau aggregates.
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Affiliation(s)
- Wanjoo Chun
- Department of Psychiatry, University of Alabama at Birmingham School of Medicine, Birmingham, Alabama 35294, USA
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Abstract
The autoimmune model of multiple sclerosis (MS) pathogenesis provided for many years a useful but incomplete conceptual framework for understanding the complex array of factors that lead to the loss of immune homeostasis, myelin and axonal injury, and progressive neurological symptoms. The availability of novel tools in molecular neurogenetics and increasingly sophisticated neuroimaging technologies, together with the revitalization of MS neuropathology, has created a new paradigm for the multidisciplinary study of this disease. This is reflected by the growing resolution of the MS genomic map, discovery of delicate inflammatory networks that are perturbed in MS, identification of mediators of demyelination, and recognition that cumulative axonal loss and neuronal injury are the histological correlates of neurological disability. Together, these advances have set the stage for the development of therapeutic approaches designed to target the demyelinating and neurodegenerative components of the disease and promote repair.
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Affiliation(s)
- Stephen L Hauser
- Department of Neurology, School of Medicine, University of California at San Francisco, San Francisco, California 94143, USA
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Chau KWK, Chan WY, Shaw PC, Chan HYE. Biochemical investigation of Tau protein phosphorylation status and its solubility properties in Drosophila. Biochem Biophys Res Commun 2006; 346:150-9. [PMID: 16759647 DOI: 10.1016/j.bbrc.2006.05.112] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2006] [Accepted: 05/13/2006] [Indexed: 12/20/2022]
Abstract
Tau hyperphosphorylation and insoluble aggregate formation are two cellular features of tauopathies. However, the contribution of Tau protein hyperphosphorylation and its aggregation to Tau pathology still remain controversial. Overexpression of human tau transgenes in the Drosophila eye is toxic and causes neuronal degeneration. We showed that human Tau protein was phosphorylated by endogenous protein kinases in flies, and overexpression of either GSK3beta or Cdk5 enhanced tau-induced toxicity. Using a dominant-negative approach, we showed that kinase activity is important for the enhancement of tau-induced toxicity. Interestingly, such enhancement was accompanied with hyperphosphorylation and alteration of protein solubility properties of Tau. This situation was reminiscent of that observed in pre-tangle neurons in tauopathies patients. We also observed age-dependent Tau aggregate formation in aged transgenic flies. In summary, tau-induced toxicity is enhanced when the human Tau protein undergoes hyperphosphorylation, and we further demonstrated that aging contributes to Tau aggregate formation. Our data also underscore the utilization of transgenic Drosophila Tau models for the studies of pre-tangle events in tauopathies.
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Affiliation(s)
- Katy Wing-Kam Chau
- Department of Biochemistry and Molecular Biotechnology Programme, The Chinese University of Hong Kong, Shatin, Hong Kong, China
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46
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Martínez A, Mas A, de las Heras V, Arroyo R, Fernández-Arquero M, de la Concha EG, Urcelay E. Early B-cell Factor gene association with multiple sclerosis in the Spanish population. BMC Neurol 2005; 5:19. [PMID: 16255771 PMCID: PMC1291372 DOI: 10.1186/1471-2377-5-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2005] [Accepted: 10/28/2005] [Indexed: 01/01/2023] Open
Abstract
Background The etiology of multiple sclerosis (MS) is at present not fully elucidated, although it is considered to result from the interaction of environmental and genetic susceptibility factors. In this work we aimed at testing the Early B-cell Factor (EBF1) gene as a functional and positional candidate risk factor for this neurological disease. Axonal damage is a hallmark for multiple sclerosis clinical disability and EBF plays an evolutionarily conserved role in the expression of proteins essential for axonal pathfinding. Failure of B-cell differentiation was found in EBF-deficient mice and involvement of B-lymphocytes in MS has been suggested from their presence in cerebrospinal fluid and lesions of patients. Methods The role of the EBF1 gene in multiple sclerosis susceptibility was analyzed by performing a case-control study with 356 multiple sclerosis patients and 540 ethnically matched controls comparing the EBF1 polymorphism rs1368297 and the microsatellite D5S2038. Results Significant association of an EBF1-intronic polymorphism (rs1368297, A vs. T: p = 0.02; OR = 1.26 and AA vs. [TA+TT]: p = 0.02; OR = 1.39) was discovered. This association was even stronger after stratification for the well-established risk factor of multiple sclerosis in the Major Histocompatibility Complex, DRB1*1501 (AA vs. [TA+TT]: p = 0.005; OR = 1.78). A trend for association in the case-control study of another EBF1 marker, the allele 5 of the very informative microsatellite D5S2038, was corroborated by Transmission Disequilibrium Test of 53 trios (p = 0.03). Conclusion Our data support EBF1 gene association with MS pathogenesis in the Spanish white population. Two genetic markers within the EBF1 gene have been found associated with this neurological disease, indicative either of their causative role or that of some other polymorphism in linkage disequilibrium with them.
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Affiliation(s)
- Alfonso Martínez
- Department of Clinical Immunology, Hospital Clinico San Carlos, Madrid, Spain
| | - Ana Mas
- Department of Clinical Immunology, Hospital Clinico San Carlos, Madrid, Spain
| | | | - Rafael Arroyo
- Department of Neurology, Hospital Clinico San Carlos, Madrid, Spain
| | | | | | - Elena Urcelay
- Department of Clinical Immunology, Hospital Clinico San Carlos, Madrid, Spain
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Bartosik-Psujek H, Stelmasiak Z. The CSF levels of total-tau and phosphotau in patients with relapsing-remitting multiple sclerosis. J Neural Transm (Vienna) 2005; 113:339-45. [PMID: 15997419 DOI: 10.1007/s00702-005-0327-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2005] [Accepted: 04/30/2005] [Indexed: 10/25/2022]
Abstract
Total-tau protein is considered the marker of axon damage whereas the abnormally phosphorylated tau forms are mainly associated with Alzheimer's disease. An increase in total-tau levels was observed in neurodegenerative diseases, including multiple sclerosis (MS). In order to find out whether the phosphorylated tau forms occur in MS patients and to evaluate their clinical significance, the levels of total-tau (t-tau) and tau phosphorylated at Thr 181 (p-tau) were determined in 60 MS patients (40 during relapse including 18 with the first relapse and 20 stable) and in 18 age-matched controls. The determinations were conducted in the cerebrospinal fluid (CSF) using the ELISA method. The levels of t-tau and p-tau were higher in MS patients than in controls; however, increased levels were not related to the clinical activity of the disease. In CSF of the patients with the first relapse the level of t-tau was significantly increased whilst the level of p-tau was not elevated.
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Affiliation(s)
- H Bartosik-Psujek
- Department of Neurology, Medical University of Lublin, Lublin, Poland.
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