1
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Xie L, Raj Y, Varathan P, He B, Yu M, Nho K, Salama P, Saykin AJ, Yan J. Deep Trans-Omic Network Fusion for Molecular Mechanism of Alzheimer's Disease. J Alzheimers Dis 2024; 99:715-727. [PMID: 38728189 DOI: 10.3233/jad-240098] [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] [Indexed: 05/12/2024]
Abstract
Background There are various molecular hypotheses regarding Alzheimer's disease (AD) like amyloid deposition, tau propagation, neuroinflammation, and synaptic dysfunction. However, detailed molecular mechanism underlying AD remains elusive. In addition, genetic contribution of these molecular hypothesis is not yet established despite the high heritability of AD. Objective The study aims to enable the discovery of functionally connected multi-omic features through novel integration of multi-omic data and prior functional interactions. Methods We propose a new deep learning model MoFNet with improved interpretability to investigate the AD molecular mechanism and its upstream genetic contributors. MoFNet integrates multi-omic data with prior functional interactions between SNPs, genes, and proteins, and for the first time models the dynamic information flow from DNA to RNA and proteins. Results When evaluated using the ROS/MAP cohort, MoFNet outperformed other competing methods in prediction performance. It identified SNPs, genes, and proteins with significantly more prior functional interactions, resulting in three multi-omic subnetworks. SNP-gene pairs identified by MoFNet were mostly eQTLs specific to frontal cortex tissue where gene/protein data was collected. These molecular subnetworks are enriched in innate immune system, clearance of misfolded proteins, and neurotransmitter release respectively. We validated most findings in an independent dataset. One multi-omic subnetwork consists exclusively of core members of SNARE complex, a key mediator of synaptic vesicle fusion and neurotransmitter transportation. Conclusions Our results suggest that MoFNet is effective in improving classification accuracy and in identifying multi-omic markers for AD with improved interpretability. Multi-omic subnetworks identified by MoFNet provided insights of AD molecular mechanism with improved details.
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Affiliation(s)
- Linhui Xie
- Department of Electrical and Computer Engineering, Indiana University Purdue University Indianapolis, Indianapolis, IN, USA
- Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA
| | - Yash Raj
- Department of BioHealth Informatics, Indiana University Purdue University Indianapolis, Indianapolis, IN, USA
| | - Pradeep Varathan
- Department of BioHealth Informatics, Indiana University Purdue University Indianapolis, Indianapolis, IN, USA
- Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA
| | - Bing He
- Department of BioHealth Informatics, Indiana University Purdue University Indianapolis, Indianapolis, IN, USA
- Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA
| | - Meichen Yu
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
- Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA
| | - Kwangsik Nho
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
- Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA
| | - Paul Salama
- Department of Electrical and Computer Engineering, Indiana University Purdue University Indianapolis, Indianapolis, IN, USA
| | - Andrew J Saykin
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
- Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA
| | - Jingwen Yan
- Department of BioHealth Informatics, Indiana University Purdue University Indianapolis, Indianapolis, IN, USA
- Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA
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2
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Banerjee S, Banerjee S. Amyloid Beta-Mediated Neurovascular Toxicity in Alzheimer's Disease. Methods Mol Biol 2024; 2761:355-372. [PMID: 38427250 DOI: 10.1007/978-1-0716-3662-6_26] [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] [Indexed: 03/02/2024]
Abstract
The brain vascular system receives one-fifth of the total oxygen from the cardiac output, and this transport system is highly dependent on blood-brain barrier (BBB) integrity. The cerebral blood flow is controlled by neurovascular coupling through neurovascular units (NVUs). The NVU includes different types of cells, such as mural cells, astrocytes, pericytes, endothelial cells (ECs), and vascular smooth muscle cells (VSMCs). The cellular composition of NVU varies throughout the vascular tree. Amyloid β (Aβ) is abundantly present in the central nervous system, but the pathological accumulation of misfolded Aβ protein causes vascular damage, resulting in neurovascular dysfunction. Aβ aggregation can activate the astrocytes and endothelial cells. It is followed by pericyte degeneration which results in dysregulation of cerebral blood flow (CBF), neurovascular uncoupling, and BBB breakdown. Thus, understanding the cellular and molecular mechanisms of Aβ-induced neurovascular toxicity is crucial for determining normal and diseased brain function. This chapter discusses the components of NVU, neurovascular uncoupling, Aβ-induced cerebrovascular reactivity, and cerebral blood flow reduction in neurodegenerative disorders, with special emphasis on Alzheimer's disease.
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Affiliation(s)
- Sayani Banerjee
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research, Kolkata, India
| | - Sugato Banerjee
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research, Kolkata, India
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3
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Wang N, Yang X, Zhao Z, Liu D, Wang X, Tang H, Zhong C, Chen X, Chen W, Meng Q. Cooperation between neurovascular dysfunction and Aβ in Alzheimer's disease. Front Mol Neurosci 2023; 16:1227493. [PMID: 37654789 PMCID: PMC10466809 DOI: 10.3389/fnmol.2023.1227493] [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: 05/23/2023] [Accepted: 08/02/2023] [Indexed: 09/02/2023] Open
Abstract
The amyloid-β (Aβ) hypothesis was once believed to represent the pathogenic process of Alzheimer's disease (AD). However, with the failure of clinical drug development and the increasing understanding of the disease, the Aβ hypothesis has been challenged. Numerous recent investigations have demonstrated that the vascular system plays a significant role in the course of AD, with vascular damage occurring prior to the deposition of Aβ and neurofibrillary tangles (NFTs). The question of how Aβ relates to neurovascular function and which is the trigger for AD has recently come into sharp focus. In this review, we outline the various vascular dysfunctions associated with AD, including changes in vascular hemodynamics, vascular cell function, vascular coverage, and blood-brain barrier (BBB) permeability. We reviewed the most recent findings about the complicated Aβ-neurovascular unit (NVU) interaction and highlighted its vital importance to understanding disease pathophysiology. Vascular defects may lead to Aβ deposition, neurotoxicity, glial cell activation, and metabolic dysfunction; In contrast, Aβ and oxidative stress can aggravate vascular damage, forming a vicious cycle loop.
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Affiliation(s)
- Niya Wang
- Department of Neurology, The First People’s Hospital of Yunnan Province, Kunming, China
- The Affiliated Hospital of Kunming University of Science and Technology, Kunming, China
| | - Xiang Yang
- Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Zhong Zhao
- Department of Neurology, The First People’s Hospital of Yunnan Province, Kunming, China
- The Affiliated Hospital of Kunming University of Science and Technology, Kunming, China
| | - Da Liu
- Department of Neurology, The First People’s Hospital of Yunnan Province, Kunming, China
- The Affiliated Hospital of Kunming University of Science and Technology, Kunming, China
| | - Xiaoyan Wang
- Department of Neurology, The First People’s Hospital of Yunnan Province, Kunming, China
- The Affiliated Hospital of Kunming University of Science and Technology, Kunming, China
| | - Hao Tang
- Department of Neurology, The First People’s Hospital of Yunnan Province, Kunming, China
- The Affiliated Hospital of Kunming University of Science and Technology, Kunming, China
| | - Chuyu Zhong
- Department of Neurology, The First People’s Hospital of Yunnan Province, Kunming, China
- The Affiliated Hospital of Kunming University of Science and Technology, Kunming, China
| | - Xinzhang Chen
- Department of Neurology, The First People’s Hospital of Yunnan Province, Kunming, China
- The Affiliated Hospital of Kunming University of Science and Technology, Kunming, China
| | - Wenli Chen
- Department of Neurology, The First People’s Hospital of Yunnan Province, Kunming, China
- The Affiliated Hospital of Kunming University of Science and Technology, Kunming, China
| | - Qiang Meng
- Department of Neurology, The First People’s Hospital of Yunnan Province, Kunming, China
- The Affiliated Hospital of Kunming University of Science and Technology, Kunming, China
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4
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Mehta SL, Kim T, Chelluboina B, Vemuganti R. Tau and GSK-3β are Critical Contributors to α-Synuclein-Mediated Post-Stroke Brain Damage. Neuromolecular Med 2023; 25:94-101. [PMID: 36447045 PMCID: PMC10249510 DOI: 10.1007/s12017-022-08731-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 11/13/2022] [Indexed: 12/03/2022]
Abstract
Post-stroke secondary brain damage is significantly influenced by the induction and accumulation of α-Synuclein (α-Syn). α-Syn-positive inclusions are often present in tauopathies and elevated tau levels and phosphorylation promotes neurodegeneration. Glycogen synthase kinase 3β (GSK-3β) is a known promoter of tau phosphorylation. We currently evaluated the interaction of α-Syn with GSK-3β and tau in post-ischemic mouse brain. Transient focal ischemia led to increased cerebral protein-protein interaction of α-Syn with both GSK-3β and tau and elevated tau phosphorylation. Treatment with a GSK-3β inhibitor prevented post-ischemic tau phosphorylation. Furthermore, α-Syn interaction was observed to be crucial for post-ischemic GSK-3β-dependent tau hyperphosphorylation as it was not seen in α-Syn knockout mice. Moreover, tau knockout mice show significantly smaller brain damage after transient focal ischemia. Overall, the present study indicates that GSK-3β catalyzes the α-Syn-dependent tau phosphorylation and preventing this interaction is crucial to limit post-ischemic secondary brain damage.
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Affiliation(s)
- Suresh L Mehta
- Department of Neurological Surgery, University of Wisconsin-Madison, Mail Code CSC-8660, 600 Highland Ave, Madison, WI, 53792, USA
| | - TaeHee Kim
- Department of Neurological Surgery, University of Wisconsin-Madison, Mail Code CSC-8660, 600 Highland Ave, Madison, WI, 53792, USA
| | - Bharath Chelluboina
- Department of Neurological Surgery, University of Wisconsin-Madison, Mail Code CSC-8660, 600 Highland Ave, Madison, WI, 53792, USA
| | - Raghu Vemuganti
- Department of Neurological Surgery, University of Wisconsin-Madison, Mail Code CSC-8660, 600 Highland Ave, Madison, WI, 53792, USA.
- William S. Middleton Veterans Administration Hospital, Madison, WI, USA.
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5
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Cardozo CF, Vera A, Quintana-Peña V, Arango-Davila CA, Rengifo J. Regulation of Tau protein phosphorylation by glucosamine-induced O-GlcNAcylation as a neuroprotective mechanism in a brain ischemia-reperfusion model. Int J Neurosci 2023; 133:194-200. [PMID: 33736564 DOI: 10.1080/00207454.2021.1901695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Purpose:Tau hyperphosphorylation is a modification frequently observed after brain ischemia which has been related to the aggregation of this protein, with subsequent cytoskeletal damage, and cellular toxicity. The present study tests the hypothesis of using glucosamine, an agent that increases protein O-GlcNAcylation, to decrease the levels of phosphorylation in Tau during ischemia-reperfusion.Material and methods: Transient focal ischemia was artificially induced in male Wistar rats by occlusion of the middle cerebral artery (MCAO) with an intraluminal monofilament. A single dose of intraperitoneal glucosamine of 200 mg/kg diluted in normal saline (SSN) was administered 60 min before ischemia. Histological brain sections were processed using indirect immunofluorescence with primary antibodies (anti-O-GlcNAc and anti pTau-ser 396). The Image J software was used to calculate the immunofluorescence signal intensity.Results: The phosphorylation of Tau at the serine residue 396 had a significant decrease with the administration of glucosamine during ischemia-reperfusion compared with the administration of placebo.Conclusions: These results show that glucosamine can reduce the phosphorylation levels of Tau in rodents subjected to ischemia and cerebral reperfusion, which implies a neuroprotective role of glucosamine.
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Affiliation(s)
- C F Cardozo
- Escuela de Ciencias Básicas, Universidad del Valle, Cali, Colombia.,Facultad de Ciencias Naturales, Universidad Icesi, Cali, Colombia
| | - A Vera
- Departamento de Ciencias Básicas, Universidad de Caldas, Manizales, Colombia
| | - V Quintana-Peña
- Facultad de Ciencias de la Salud, Universidad Icesi, Cali, Colombia
| | - C A Arango-Davila
- Facultad de Ciencias de la Salud, Universidad Icesi, Cali, Colombia.,Fundación Valle del Lili, Cali, Colombia
| | - J Rengifo
- Facultad de Ciencias Naturales, Universidad Icesi, Cali, Colombia
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6
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Custodia A, Ouro A, Romaus-Sanjurjo D, Pías-Peleteiro JM, de Vries HE, Castillo J, Sobrino T. Endothelial Progenitor Cells and Vascular Alterations in Alzheimer’s Disease. Front Aging Neurosci 2022; 13:811210. [PMID: 35153724 PMCID: PMC8825416 DOI: 10.3389/fnagi.2021.811210] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 12/14/2021] [Indexed: 12/14/2022] Open
Abstract
Alzheimer’s disease (AD) is a neurodegenerative disease representing the most common type of dementia worldwide. The early diagnosis of AD is very difficult to achieve due to its complexity and the practically unknown etiology. Therefore, this is one of the greatest challenges in the field in order to develop an accurate therapy. Within the different etiological hypotheses proposed for AD, we will focus on the two-hit vascular hypothesis and vascular alterations occurring in the disease. According to this hypothesis, the accumulation of β-amyloid protein in the brain starts as a consequence of damage in the cerebral vasculature. Given that there are several vascular and angiogenic alterations in AD, and that endothelial progenitor cells (EPCs) play a key role in endothelial repair processes, the study of EPCs in AD may be relevant to the disease etiology and perhaps a biomarker and/or therapeutic target. This review focuses on the involvement of endothelial dysfunction in the onset and progression of AD with special emphasis on EPCs as a biomarker and potential therapeutic target.
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Affiliation(s)
- Antía Custodia
- NeuroAging Group (NEURAL), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - Alberto Ouro
- NeuroAging Group (NEURAL), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
- *Correspondence: Alberto Ouro,
| | - Daniel Romaus-Sanjurjo
- NeuroAging Group (NEURAL), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - Juan Manuel Pías-Peleteiro
- NeuroAging Group (NEURAL), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - Helga E. de Vries
- Neuroimmunology Research Group, Department of Molecular Cell Biology and Immunology, Amsterdam Neuroscience, Amsterdam UMC, Amsterdam, Netherlands
| | - José Castillo
- Neuroimaging and Biotechnology Laboratory (NOBEL), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - Tomás Sobrino
- NeuroAging Group (NEURAL), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
- Tomás Sobrino,
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7
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Pluta R, Czuczwar SJ, Januszewski S, Jabłoński M. The Many Faces of Post-Ischemic Tau Protein in Brain Neurodegeneration of the Alzheimer's Disease Type. Cells 2021; 10:cells10092213. [PMID: 34571862 PMCID: PMC8465797 DOI: 10.3390/cells10092213] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 08/24/2021] [Accepted: 08/25/2021] [Indexed: 12/13/2022] Open
Abstract
Recent data suggest that post-ischemic brain neurodegeneration in humans and animals is associated with the modified tau protein in a manner typical of Alzheimer’s disease neuropathology. Pathological changes in the tau protein, at the gene and protein level due to cerebral ischemia, can lead to the development of Alzheimer’s disease-type neuropathology and dementia. Some studies have shown increased tau protein staining and gene expression in neurons following ischemia-reperfusion brain injury. Recent studies have found the tau protein to be associated with oxidative stress, apoptosis, autophagy, excitotoxicity, neuroinflammation, blood-brain barrier permeability, mitochondrial dysfunction, and impaired neuronal function. In this review, we discuss the interrelationship of these phenomena with post-ischemic changes in the tau protein in the brain. The tau protein may be at the intersection of many pathological mechanisms due to severe neuropathological changes in the brain following ischemia. The data indicate that an episode of cerebral ischemia activates the damage and death of neurons in the hippocampus in a tau protein-dependent manner, thus determining a novel and important mechanism for the survival and/or death of neuronal cells following ischemia. In this review, we update our understanding of proteomic and genomic changes in the tau protein in post-ischemic brain injury and present the relationship between the modified tau protein and post-ischemic neuropathology and present a positive correlation between the modified tau protein and a post-ischemic neuropathology that has characteristics of Alzheimer’s disease-type neurodegeneration.
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Affiliation(s)
- Ryszard Pluta
- Laboratory of Ischemic and Neurodegenerative Brain Research, Mossakowski Medical Research Institute, Polish Academy of Sciences, 5 Str. Pawińskiego, 02-106 Warsaw, Poland;
- Correspondence: ; Tel.: +48-22-6086-540
| | - Stanisław J. Czuczwar
- Department of Pathophysiology, Medical University of Lublin, 8b Str. Jaczewskiego, 20-090 Lublin, Poland;
| | - Sławomir Januszewski
- Laboratory of Ischemic and Neurodegenerative Brain Research, Mossakowski Medical Research Institute, Polish Academy of Sciences, 5 Str. Pawińskiego, 02-106 Warsaw, Poland;
| | - Mirosław Jabłoński
- Department of Rehabilitation and Orthopedics, Medical University of Lublin, 8 Str. Jaczewskiego, 20-090 Lublin, Poland;
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8
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Chen YD, Huang PY, Chiang CS, Huang YS, Tang SC. Generation and Role of Calpain-Cleaved 17-kDa Tau Fragment in Acute Ischemic Stroke. Mol Neurobiol 2021; 58:5814-5825. [PMID: 34414533 DOI: 10.1007/s12035-021-02519-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 08/03/2021] [Indexed: 01/04/2023]
Abstract
Stroke is the leading cause of permanent disability and death in the world. The therapy for acute stroke is still limited due to the complex mechanisms underlying stroke-induced neuronal death. The generation of a 17-kDa neurotoxic tau fragment was reported in Alzheimer's disease but it has not been well studied in stroke. In this study, we observed the accumulation of 17-kDa tau fragment in cultured primary neurons and media after oxygen-glucose deprivation/reperfusion (OGD/R) treatment that could be diminished by the presence of a calpain inhibitor. This calpain-mediated proteolytic tau fragment was also detected in brain tissues from middle cerebral artery occlusion-injured rats and acute ischemic stroke patients receiving strokectomy, and human plasma samples collected within 48 h after the onset of stroke. The mass spectrometry analysis of this 17-kDa fragment identified 2 peptide sequences containing 195-224 amino acids of tau, which agrees with the previously reported tau45-230 or tau125-230 as the calpain-cleaved tau fragment. Ectopic expression of tau45-230-GFP but not tau125-230-GFP in cultured neurons induced the formation of tortuous processes without evident cell death. In summary, the 17-kDa tau fragment is a novel stroke biomarker and may play a pathophysiological role to affect post-stroke neuronal health.
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Affiliation(s)
- Ying-Da Chen
- Stroke Center and Department of Neurology, National Taiwan University Hospital, Taipei, 100, Taiwan.,Institute of Biomedical Sciences, Academia Sinica, Taipei, 11529, Taiwan
| | - Po-Yuan Huang
- Stroke Center and Department of Neurology, National Taiwan University Hospital, Taipei, 100, Taiwan
| | - Chien-Sung Chiang
- Stroke Center and Department of Neurology, National Taiwan University Hospital, Taipei, 100, Taiwan
| | - Yi-Shuian Huang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, 11529, Taiwan. .,Neuroscience Program of Academia Sinica, Academia Sinica, Taipei, 11529, Taiwan.
| | - Sung-Chun Tang
- Stroke Center and Department of Neurology, National Taiwan University Hospital, Taipei, 100, Taiwan.
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9
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Paolini Paoletti F, Simoni S, Parnetti L, Gaetani L. The Contribution of Small Vessel Disease to Neurodegeneration: Focus on Alzheimer's Disease, Parkinson's Disease and Multiple Sclerosis. Int J Mol Sci 2021; 22:ijms22094958. [PMID: 34066951 PMCID: PMC8125719 DOI: 10.3390/ijms22094958] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 05/04/2021] [Accepted: 05/05/2021] [Indexed: 01/18/2023] Open
Abstract
Brain small vessel disease (SVD) refers to a variety of structural and functional changes affecting small arteries and micro vessels, and manifesting as white matter changes, microbleeds and lacunar infarcts. Growing evidence indicates that SVD might play a significant role in the neurobiology of central nervous system (CNS) neurodegenerative disorders, namely Alzheimer's disease (AD) and Parkinson's disease (PD), and neuroinflammatory diseases, such as multiple sclerosis (MS). These disorders share different pathophysiological pathways and molecular mechanisms (i.e., protein misfolding, derangement of cellular clearance systems, mitochondrial impairment and immune system activation) having neurodegeneration as biological outcome. In these diseases, the actual contribution of SVD to the clinical picture, and its impact on response to pharmacological treatments, is not known yet. Due to the high frequency of SVD in adult-aged patients, it is important to address this issue. In this review, we report preclinical and clinical data on the impact of SVD in AD, PD and MS, with the main aim of clarifying the predictability of SVD on clinical manifestations and treatment response.
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10
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Mankhong S, Kim S, Moon S, Lee KH, Jeon HE, Hwang BH, Beak JW, Joa KL, Kang JH. Effects of Aerobic Exercise on Tau and Related Proteins in Rats with the Middle Cerebral Artery Occlusion. Int J Mol Sci 2020; 21:ijms21165842. [PMID: 32823945 PMCID: PMC7461507 DOI: 10.3390/ijms21165842] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/10/2020] [Accepted: 08/12/2020] [Indexed: 11/16/2022] Open
Abstract
Although Alzheimer's disease (AD)-like pathology is frequently found in patients with post-stroke dementia, little is known about the effects of aerobic exercise on the modifications of tau and related proteins. Therefore, we evaluated the effects of aerobic exercise on the phosphorylation and acetylation of tau and the expressions of tau-related proteins, after middle cerebral artery occlusion (MCAO) stroke. Twenty-four Sprague-Dawley rats with MCAO infarction were used in this study. The rehabilitation group (RG) received treadmill training 40 min/day for 12 weeks, whereas the sedentary group (SG) did not receive any type of training. Functional tests, such as the single pellet reaching task, rotarod, and radial arm maze tests, were performed monthly for 3 months. In ipsilateral cortices in the RG and SG groups, level of Ac-tau was lower in the RG, whereas levels of p-tauS396, p-tauS262, and p-tauS202/T205 were not significantly lower in the RG. Level of phosphorylated glycogen synthase kinase 3-beta Tyr 216 (p-GSK3βY216) was lower in the RG, but levels of p-AMPK and phosphorylated glycogen synthase kinase 3-beta Ser 9 (p-GSK3βS9) were not significantly lower. Levels of COX-2 and BDNF were not significantly different between the two groups, while SIRT1 significantly decreased in ipsilateral cortices in RG. In addition, aerobic training also improved motor, balance, and memory functions. Rehabilitation with aerobic exercise inhibited tau modification, especially tau acetylation, following infarction in the rat MCAO model, which was accompanied with the improvement of motor and cognitive functions.
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Affiliation(s)
- Sakulrat Mankhong
- Department of Pharmacology, College of Medicine, Inha University, Incheon 22212, Korea; (S.M.); (S.K.); (S.M.)
- Hypoxia-Related Diseases Research Center, College of Medicine, Inha University, Incheon 22212, Korea
| | - Sujin Kim
- Department of Pharmacology, College of Medicine, Inha University, Incheon 22212, Korea; (S.M.); (S.K.); (S.M.)
- Hypoxia-Related Diseases Research Center, College of Medicine, Inha University, Incheon 22212, Korea
| | - Sohee Moon
- Department of Pharmacology, College of Medicine, Inha University, Incheon 22212, Korea; (S.M.); (S.K.); (S.M.)
- Hypoxia-Related Diseases Research Center, College of Medicine, Inha University, Incheon 22212, Korea
| | - Kyoung-Hee Lee
- Department of Occupational Therapy, Baekseok University, Chungnam 31065, Korea;
| | - Hyeong-Eun Jeon
- Department of Physical & Rehabilitation Medicine, College of Medicine, Inha University, Incheon 22332, Korea;
| | - Byeong-Hun Hwang
- Industry-Academia Cooperation Group, Baekseok University, Chungnam 31065, Korea; (B.-H.H.); (J.-W.B.)
| | - Jong-Won Beak
- Industry-Academia Cooperation Group, Baekseok University, Chungnam 31065, Korea; (B.-H.H.); (J.-W.B.)
| | - Kyung-Lim Joa
- Department of Physical & Rehabilitation Medicine, College of Medicine, Inha University, Incheon 22332, Korea;
- Correspondence: (K.-L.J.); (J.-H.K.); Tel.: +82-890-2480 (K.-L.J.); +82-32-860-9872 (J.-H.K.)
| | - Ju-Hee Kang
- Department of Pharmacology, College of Medicine, Inha University, Incheon 22212, Korea; (S.M.); (S.K.); (S.M.)
- Hypoxia-Related Diseases Research Center, College of Medicine, Inha University, Incheon 22212, Korea
- Correspondence: (K.-L.J.); (J.-H.K.); Tel.: +82-890-2480 (K.-L.J.); +82-32-860-9872 (J.-H.K.)
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11
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Chen X, Jiang H. Tau as a potential therapeutic target for ischemic stroke. Aging (Albany NY) 2019; 11:12827-12843. [PMID: 31841442 PMCID: PMC6949092 DOI: 10.18632/aging.102547] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 11/19/2019] [Indexed: 12/12/2022]
Abstract
Tau is a protein mainly expressed in adult human brain. It plays important roles both in neurodegenerative diseases and stroke. Stroke is an important cause of adult death and disability, ischemic stroke almost account for 80% in all cases. Abundant studies have proven that the increase of dysfunctional tau may act as a vital factor in pathological changes after ischemic stroke. However, the relationship between tau and ischemic stroke remains ununified. Based on present studies, we firstly introduced the structure and biological function of tau protein. Secondly, we summarized the potential regulatory mechanisms of tau protein in the process of ischemic stroke. Thirdly, we discussed about the findings in therapeutic researches of ischemic stroke. This review may be helpful in implementing new therapies for ischemic stroke and may be beneficial for the clinical and experimental studies.
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Affiliation(s)
- Xin Chen
- Department of Geriatrics, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Hua Jiang
- Department of Geriatrics, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
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12
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Pluta R, Ułamek-Kozioł M, Januszewski S, Czuczwar SJ. Tau Protein Dysfunction after Brain Ischemia. J Alzheimers Dis 2019; 66:429-437. [PMID: 30282370 PMCID: PMC6218135 DOI: 10.3233/jad-180772] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Brain ischemia comprises blood-brain barrier, glial, and neuronal cells. The blood–brain barrier controls permeability of different substances and the composition of the neuronal cells ‘milieu’, which is required for their physiological functioning. Recent evidence indicates that brain ischemia itself and ischemic blood-brain barrier dysfunction is associated with the accumulation of neurotoxic molecules within brain tissue, e.g., different parts of amyloid-β protein precursor and changed pathologically tau protein. All these changes due to ischemia can initiate and progress neurodegeneration of the Alzheimer’s disease-type. This review presents brain ischemia and ischemic blood-brain barrier as a trigger for tau protein alterations. Thus, we hypothesize that the changes in pattern of phosphorylation of tau protein are critical to microtubule function especially in neurons, and contribute to the neurodegeneration following brain ischemia-reperfusion episodes with Alzheimer’s disease phenotype.
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Affiliation(s)
- Ryszard Pluta
- Laboratory of Ischemic and Neurodegenerative Brain Research, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland
| | - Marzena Ułamek-Kozioł
- Laboratory of Ischemic and Neurodegenerative Brain Research, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland.,First Department of Neurology, Institute of Psychiatry and Neurology, Warsaw, Poland
| | - Sławomir Januszewski
- Laboratory of Ischemic and Neurodegenerative Brain Research, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland
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Ruan Q, Yu Z, Zhang W, Ruan J, Liu C, Zhang R. Cholinergic Hypofunction in Presbycusis-Related Tinnitus With Cognitive Function Impairment: Emerging Hypotheses. Front Aging Neurosci 2018; 10:98. [PMID: 29681847 PMCID: PMC5897739 DOI: 10.3389/fnagi.2018.00098] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 03/22/2018] [Indexed: 01/21/2023] Open
Abstract
Presbycusis (age-related hearing loss) is a potential risk factor for tinnitus and cognitive deterioration, which result in poor life quality. Presbycusis-related tinnitus with cognitive impairment is a common phenotype in the elderly population. In these individuals, the central auditory system shows similar pathophysiological alterations as those observed in Alzheimer's disease (AD), including cholinergic hypofunction, epileptiform-like network synchronization, chronic inflammation, and reduced GABAergic inhibition and neural plasticity. Observations from experimental rodent models indicate that recovery of cholinergic function can improve memory and other cognitive functions via acetylcholine-mediated GABAergic inhibition enhancement, nicotinic acetylcholine receptor (nAChR)-mediated anti-inflammation, glial activation inhibition and neurovascular protection. The loss of cholinergic innervation of various brain structures may provide a common link between tinnitus seen in presbycusis-related tinnitus and age-related cognitive impairment. We hypothesize a key component of the condition is the withdrawal of cholinergic input to a subtype of GABAergic inhibitory interneuron, neuropeptide Y (NPY) neurogliaform cells. Cholinergic denervation might not only cause the degeneration of NPY neurogliaform cells, but may also result in decreased AChR activation in GABAergic inhibitory interneurons. This, in turn, would lead to reduced GABA release and inhibitory regulation of neural networks. Reduced nAChR-mediated anti-inflammation due to the loss of nicotinic innervation might lead to the transformation of glial cells and release of inflammatory mediators, lowering the buffering of extracellular potassium and glutamate metabolism. Further research will provide evidence for the recovery of cholinergic function with the use of cholinergic input enhancement alone or in combination with other rehabilitative interventions to reestablish inhibitory regulation mechanisms of involved neural networks for presbycusis-related tinnitus with cognitive impairment.
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Affiliation(s)
- Qingwei Ruan
- Shanghai Institute of Geriatrics and Gerontology, Shanghai Key Laboratory of Clinical Geriatrics, Huadong Hospital, and Research Center of Aging and Medicine, Shanghai Medical College, Fudan University, Shanghai, China
| | - Zhuowei Yu
- Shanghai Institute of Geriatrics and Gerontology, Shanghai Key Laboratory of Clinical Geriatrics, Huadong Hospital, and Research Center of Aging and Medicine, Shanghai Medical College, Fudan University, Shanghai, China
| | - Weibin Zhang
- Shanghai Institute of Geriatrics and Gerontology, Shanghai Key Laboratory of Clinical Geriatrics, Huadong Hospital, and Research Center of Aging and Medicine, Shanghai Medical College, Fudan University, Shanghai, China
| | - Jian Ruan
- Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Chunhui Liu
- Department of Otolaryngology, Huadong Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Ruxin Zhang
- Department of Otolaryngology, Huadong Hospital, Shanghai Medical College, Fudan University, Shanghai, China
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14
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Rizvi B, Narkhede A, Last BS, Budge M, Tosto G, Manly JJ, Schupf N, Mayeux R, Brickman AM. The effect of white matter hyperintensities on cognition is mediated by cortical atrophy. Neurobiol Aging 2018; 64:25-32. [PMID: 29328963 PMCID: PMC5831564 DOI: 10.1016/j.neurobiolaging.2017.12.006] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 11/13/2017] [Accepted: 12/08/2017] [Indexed: 12/22/2022]
Abstract
White matter hyperintensities (WMH) have been linked to cognitive dysfunction and dementia, although the reasons are unclear. One possibility is that WMH promote neurodegeneration, which, in turn, affects cognition. We examined whether cortical thickness, a marker of neurodegeneration, mediates the relationship between WMH and cognition among 519 older adults. Using conditional process analysis modeling techniques, we examined the association between WMH volume and global cognition and tested whether cortical thickness mediates this relationship statistically. We also tested specific regional hypotheses to determine whether cortical thickness or volume in the medial temporal lobe mediates the relationship between WMH volume and memory. Increased total WMH volume was associated with poorer global cognition and memory. Global cortical thickness and medial temporal lobe thickness/volume mediated the relationship of WMH volume on global cognition and memory functioning. The mediating relationship was similar across racial and ethnic groups and across diagnostic groups (i.e., mild cognitive impairment/Alzheimer's disease). The findings suggest that WMH promote atrophy, which, in turn, drives cognitive decline and highlight a potential pathway in which small vessel cerebrovascular disease affects cognition by promoting neurodegenerative changes directly.
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Affiliation(s)
- Batool Rizvi
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Atul Narkhede
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Briana S Last
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Mariana Budge
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Giuseppe Tosto
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Gertrude H. Sergievsky Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Jennifer J Manly
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Gertrude H. Sergievsky Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Nicole Schupf
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Gertrude H. Sergievsky Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY, USA; Department of Psychiatry, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Richard Mayeux
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Gertrude H. Sergievsky Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY, USA; Department of Psychiatry, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Adam M Brickman
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Gertrude H. Sergievsky Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA.
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15
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Mavroeidi P, Mavrofrydi O, Pappa E, Panopoulou M, Papazafiri P, Haralambous S, Efthimiopoulos S. Oxygen and Glucose Deprivation Alter Synaptic Distribution of Tau Protein: The Role of Phosphorylation. J Alzheimers Dis 2017; 60:593-604. [DOI: 10.3233/jad-170157] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Panagiota Mavroeidi
- Department of Biology, Division of Animal and Human Physiology, National and Kapodistrian University of Athens, Athens, Greece
- Inflammation Research Group and Transgenic Technology Lab, Hellenic Pasteur Institute, Athens, Greece
| | - Olga Mavrofrydi
- Department of Biology, Division of Animal and Human Physiology, National and Kapodistrian University of Athens, Athens, Greece
| | - Elpiniki Pappa
- Department of Biology, Division of Animal and Human Physiology, National and Kapodistrian University of Athens, Athens, Greece
| | - Myrto Panopoulou
- Department of Biology, Division of Animal and Human Physiology, National and Kapodistrian University of Athens, Athens, Greece
| | - Panagiota Papazafiri
- Department of Biology, Division of Animal and Human Physiology, National and Kapodistrian University of Athens, Athens, Greece
| | - Sylva Haralambous
- Inflammation Research Group and Transgenic Technology Lab, Hellenic Pasteur Institute, Athens, Greece
| | - Spiros Efthimiopoulos
- Department of Biology, Division of Animal and Human Physiology, National and Kapodistrian University of Athens, Athens, Greece
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Tau exacerbates excitotoxic brain damage in an animal model of stroke. Nat Commun 2017; 8:473. [PMID: 28883427 PMCID: PMC5589746 DOI: 10.1038/s41467-017-00618-0] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 07/13/2017] [Indexed: 02/07/2023] Open
Abstract
Neuronal excitotoxicity induced by aberrant excitation of glutamatergic receptors contributes to brain damage in stroke. Here we show that tau-deficient (tau−/−) mice are profoundly protected from excitotoxic brain damage and neurological deficits following experimental stroke, using a middle cerebral artery occlusion with reperfusion model. Mechanistically, we show that this protection is due to site-specific inhibition of glutamate-induced and Ras/ERK-mediated toxicity by accumulation of Ras-inhibiting SynGAP1, which resides in a post-synaptic complex with tau. Accordingly, reducing SynGAP1 levels in tau−/− mice abolished the protection from pharmacologically induced excitotoxicity and middle cerebral artery occlusion-induced brain damage. Conversely, over-expression of SynGAP1 prevented excitotoxic ERK activation in wild-type neurons. Our findings suggest that tau mediates excitotoxic Ras/ERK signaling by controlling post-synaptic compartmentalization of SynGAP1. Excitotoxicity contributes to neuronal injury following stroke. Here the authors show that tau promotes excitotoxicity by a post-synaptic mechanism, involving site-specific control of ERK activation, in a mouse model of stroke.
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17
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Fujii H, Takahashi T, Mukai T, Tanaka S, Hosomi N, Maruyama H, Sakai N, Matsumoto M. Modifications of tau protein after cerebral ischemia and reperfusion in rats are similar to those occurring in Alzheimer's disease - Hyperphosphorylation and cleavage of 4- and 3-repeat tau. J Cereb Blood Flow Metab 2017; 37:2441-2457. [PMID: 27629097 PMCID: PMC5531343 DOI: 10.1177/0271678x16668889] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Epidemiological studies have suggested a close relationship between cerebral ischemia and Alzheimer's disease (AD). To clarify the pathological association of tau dynamics in both diseases, we performed comprehensive studies on the posttranslational modification of tau in cerebral ischemia and reperfusion (I/R) in rats. The present study suggests that both 4-repeat and 3-repeat tau isoforms are hyperphosphorylated in cerebral I/R, similar to the case in AD. The generation of a 60-kDa Asp421-truncated tau in cerebral I/R preceded the emergence of a 17-kDa 3-repeat tau fragment and a 25-kDa 4-repeat tau fragment. The regional redistribution of tau from the neuropil to neuronal perikarya in our stroke model is thought to share similarity with that occurring in AD. In addition, immunofluorescence staining revealed the formation of axonal varicosities in cerebral I/R. Altered tau distribution may influence microtubule stability, disturbances in axonal transport, and the resulting formation of axonal varicosities. The staining profiles of granules in the ischemic cortex that were immunopositive for RD3, RD4, and AT8 in neuronal perikarya and that were argyrophilic on Gallyas-Braak staining were similar to those in AD. These findings suggest that transient cerebral ischemia shares a common pathology with AD, in the modification of tau protein.
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Affiliation(s)
- Hiroki Fujii
- 1 Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Tetsuya Takahashi
- 1 Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Tomoya Mukai
- 1 Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan.,2 Department of Stroke Medicine, Kawasaki Medical School Hospital, Kawasaki, Japan
| | - Shigeru Tanaka
- 3 Department of Molecular and Pharmacological Neuroscience, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Naohisa Hosomi
- 1 Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Hirofumi Maruyama
- 1 Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Norio Sakai
- 3 Department of Molecular and Pharmacological Neuroscience, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Masayasu Matsumoto
- 1 Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
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18
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Effects of task-specific rehabilitation training on tau modification in rat with photothrombotic cortical ischemic damage. Neurochem Int 2017; 108:309-317. [PMID: 28499951 DOI: 10.1016/j.neuint.2017.05.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 05/02/2017] [Accepted: 05/08/2017] [Indexed: 01/05/2023]
Abstract
Although stroke elicits progressive cognitive decline and is a leading cause of dementia, molecular interplay between stroke and Alzheimer's disease (AD) pathology has not been fully elucidated. Furthermore, studies on the effects of post-stroke rehabilitation on AD pathology are limited. We evaluated the acute effect of stroke on tau modification, and the molecular effects of task-specific training (TST) on tau modification using a model of photochemically-induced thrombosis (PIT)-induced cortical infarction. Following PIT in the dominant side of sensorimotor cortex, the rehabilitation group received 4-weeks of TST rehabilitation once daily by single pellet reaching training, whereas the sedentary control group did not received any type of training. Cortical expression levels of proteins related to tau modification were evaluated on post-stroke day 1 (PSD1) and 28; functional tests were also evaluated performed every week. The expression levels of acetyl-tau, phosphorylated-tau (p-tau), cyclooxygenase-2 and Akt-mTORC1-p70S6K pathway in infarcted cortices on PSD1 were significantly greater, whereas the expression levels of p-AMPK were significantly lower than in the paired contralateral sides. TST rehabilitation for 4 weeks greatly improved functional motor performance but not memory, which concurred with the down-regulations of ipsilateral p-AMPK, cyclooxygenase-2, Akt-mTORC1-p70S6K pathway, and p-tau in rehabilitation group. PIT-induced cortical infarction was found to induce cortical tau modification through the Akt-mTORC1-p70S6K activation, and to suppress the expression of AMPK-related proteins. TST rehabilitation greatly improved motor function, but not memory, and suppressed p-tau expression and neuroinflammation. Nevertheless, the role of TST-mediated regulation of tau hyperphosphorylation required further clarification.
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19
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Ułamek-Kozioł M, Pluta R, Bogucka-Kocka A, Januszewski S, Kocki J, Czuczwar SJ. Brain ischemia with Alzheimer phenotype dysregulates Alzheimer's disease-related proteins. Pharmacol Rep 2016; 68:582-91. [PMID: 26940197 DOI: 10.1016/j.pharep.2016.01.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Revised: 01/12/2016] [Accepted: 01/14/2016] [Indexed: 02/04/2023]
Abstract
There are evidences for the influence of Alzheimer's proteins on postischemic brain injury. We present here an overview of the published evidence underpinning the relationships between β-amyloid peptide, hyperphosphorylated tau protein, presenilins, apolipoproteins, secretases and neuronal survival/death decisions after ischemia and development of postischemic dementia. The interactions of above molecules and their influence and contribution to final ischemic brain degeneration resulting in dementia of Alzheimer phenotype are reviewed. Generation and deposition of β-amyloid peptide and tau protein pathology are essential factors involved in Alzheimer's disease development as well as in postischemic brain dementia. Postischemic injuries demonstrate that ischemia may stimulate pathological amyloid precursor protein processing by upregulation of β- and γ-secretases and therefore are capable of establishing a vicious cycle. Functional postischemic brain recovery is always delayed and incomplete by an injury-related increase in the amount of the neurotoxic C-terminal of amyloid precursor protein and β-amyloid peptide. Finally, we present here the concept that Alzheimer's proteins can contribute to and/or precipitate postischemic brain neurodegeneration including dementia with Alzheimer's phenotype.
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Affiliation(s)
- Marzena Ułamek-Kozioł
- Laboratory of Ischemic and Neurodegenerative Brain Research, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warszawa, Poland
| | - Ryszard Pluta
- Laboratory of Ischemic and Neurodegenerative Brain Research, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warszawa, Poland.
| | - Anna Bogucka-Kocka
- Department of Pharmaceutical Botany, Medical University of Lublin, Lublin, Poland
| | - Sławomir Januszewski
- Laboratory of Ischemic and Neurodegenerative Brain Research, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warszawa, Poland
| | - Janusz Kocki
- Department of Clinical Genetics, Medical University of Lublin, Lublin, Poland
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20
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Won JS, Annamalai B, Choi S, Singh I, Singh AK. S-nitrosoglutathione reduces tau hyper-phosphorylation and provides neuroprotection in rat model of chronic cerebral hypoperfusion. Brain Res 2015; 1624:359-369. [PMID: 26271717 DOI: 10.1016/j.brainres.2015.07.057] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 07/08/2015] [Accepted: 07/31/2015] [Indexed: 12/21/2022]
Abstract
We have previously reported that treatment of rats subjected to permanent bilateral common carotid artery occlusion (pBCCAO), a model of chronic cerebral hypoperfusion (CCH), with S-nitrosoglutathione (GSNO), an endogenous nitric oxide carrier, improved cognitive functions and decreased amyloid-β accumulation in the brains. Since CCH has been implicated in tau hyperphosphorylation induced neurodegeneration, we investigated the role of GSNO in regulation of tau hyperphosphorylation in rat pBCCAO model. The rats subjected to pBCCAO had a significant increase in tau hyperphosphorylation with increased neuronal loss in hippocampal/cortical areas. GSNO treatment attenuated not only the tau hyperphosphorylation, but also the neurodegeneration in pBCCAO rat brains. The pBCCAO rat brains also showed increased activities of GSK-3β and Cdk5 (major tau kinases) and GSNO treatment significantly attenuated their activities. GSNO attenuated the increased calpain activities and calpain-mediated cleavage of p35 leading to production of p25 and aberrant Cdk5 activation. In in vitro studies using purified calpain protein, GSNO treatment inhibited calpain activities while 3-morpholinosydnonimine (a donor of peroxynitrite) treatment increased its activities, suggesting the opposing role of GSNO vs. peroxynitrite in regulation of calpain activities. In pBCCAO rat brains, GSNO treatment attenuated the expression of inducible nitric oxide synthase (iNOS) expression and also reduced the brain levels of nitro-tyrosine formation, thereby indicating the protective role of GSNO in iNOS/nitrosative-stress mediated calpain/tau pathologies under CCH conditions. Taken together with our previous report, these data support the therapeutic potential of GSNO, a biological NO carrier, as a neuro- and cognitive-protective agent under conditions of CCH.
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Affiliation(s)
- Je-Seong Won
- Department of Pathology, Medical University of South Carolina, USA
| | | | - Seungho Choi
- Department of Pediatrics, Medical University of South Carolina, USA
| | - Inderjit Singh
- Department of Pediatrics, Medical University of South Carolina, USA
| | - Avtar K Singh
- Department of Pathology, Medical University of South Carolina, USA; Pathology and Laboratory Medicine Service, Ralph H. Johnson Veterans Administration Medical Center, Charleston, SC, USA.
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21
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Janota C, Lemere CA, Brito MA. Dissecting the Contribution of Vascular Alterations and Aging to Alzheimer's Disease. Mol Neurobiol 2015; 53:3793-3811. [PMID: 26143259 DOI: 10.1007/s12035-015-9319-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2015] [Accepted: 06/24/2015] [Indexed: 12/31/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease characterized by cognitive decline that afflicts as many as 45 % of individuals who survive past the age of 85. AD has been associated with neurovascular dysfunction and brain accumulation of amyloid-β peptide, as well as tau phosphorylation and neurodegeneration, but the pathogenesis of the disease is still somewhat unclear. According to the amyloid cascade hypothesis of AD, accumulation of amyloid-β peptide (Aβ) aggregates initiates a sequence of events leading to neuronal injury and loss, and dementia. Alternatively, the vascular hypothesis of AD incorporates the vascular contribution to the disease, stating that a primary insult to brain microcirculation (e.g., stroke) not only contributes to amyloidopathy but initiates a non-amyloidogenic pathway of vascular-mediated neuronal dysfunction and injury, which involves blood-brain barrier compromise, with increased permeability of blood vessels, leakage of blood-borne components into the brain, and, consequently, neurotoxicity. Vascular dysfunction also includes a diminished brain capillary flow, causing multiple focal ischemic or hypoxic microinjuries, diminished amyloid-β clearance, and formation of neurotoxic oligomers, which lead to neuronal dysfunction. Here we present and discuss relevant findings on the contribution of vascular alterations during aging to AD, with the hope that a better understanding of the players in the "orchestra" of neurodegeneration will be useful in developing therapies to modulate the "symphony".
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Affiliation(s)
- Cátia Janota
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Avenida Professor Gama Pinto, 1649-003, Lisbon, Portugal
| | - Cynthia A Lemere
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, 77 Avenue Louis Pasteur (NRB 636F), Boston, MA, 02115, USA
| | - Maria Alexandra Brito
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Avenida Professor Gama Pinto, 1649-003, Lisbon, Portugal. .,Department of Biochemistry and Human Biology, Faculdade de Farmácia, Universidade de Lisboa, Avenida Professor Gama Pinto, 1649-003, Lisbon, Portugal.
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22
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Ginsenoside Rd attenuates tau protein phosphorylation via the PI3K/AKT/GSK-3β pathway after transient forebrain ischemia. Neurochem Res 2014; 39:1363-73. [PMID: 24792734 DOI: 10.1007/s11064-014-1321-3] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Revised: 04/16/2014] [Accepted: 04/25/2014] [Indexed: 01/17/2023]
Abstract
Phosphorylated tau was found to be regulated after cerebral ischemia and linked to high risk for the development of post-stroke dementia. Our previous study showed that ginsenoside Rd (Rd), one of the main active ingredients in Panax ginseng, decreased tau phosphorylation in Alzheimer model. As an extending study, here we investigated whether Rd could reduce tau phosphorylation and sequential cognition impairment after ischemic stroke. Sprague-Dawley rats were subjected to focal cerebral ischemia. The tau phosphorylation of rat brains were analyzed following ischemia by Western blot and animal cognitive functions were examined by Morris water maze and Novel object recognition task. Ischemic insults increased the levels of phosphorylated tau protein at Ser199/202 and PHF-1 sites and caused animal memory deficits. Rd treatment attenuated ischemia-induced enhancement of tau phosphorylation and ameliorated behavior impairment. Furthermore, we revealed that Rd inhibited the activity of Glycogen synthase kinase-3β (GSK-3β), the most important kinase involving tau phosphorylation, but enhanced the activity of protein kinase B (PKB/AKT), a key kinase suppressing GSK-3β activity. Moreover, we found that LY294002, an antagonist for phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathway, abolished the inhibitory effect of Rd on GSK-3β activity and tau phosphorylation. Taken together, our findings provide the first evidence that Rd may reduce cerebral ischemia-induced tau phosphorylation via the PI3K/AKT/GSK-3β pathway.
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23
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Egea J, Romero A, Parada E, León R, Dal-Cim T, López M. Neuroprotective effect of dimebon against ischemic neuronal damage. Neuroscience 2014; 267:11-21. [DOI: 10.1016/j.neuroscience.2014.02.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2014] [Accepted: 02/19/2014] [Indexed: 02/06/2023]
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24
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Povellato G, Tuxworth RI, Hanger DP, Tear G. Modification of the Drosophila model of in vivo Tau toxicity reveals protective phosphorylation by GSK3β. Biol Open 2014; 3:1-11. [PMID: 24429107 PMCID: PMC3892155 DOI: 10.1242/bio.20136692] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Accepted: 10/29/2013] [Indexed: 01/17/2023] Open
Abstract
Hyperphosphorylation of the microtubule associated protein, Tau, is the hallmark of a group of neurodegenerative disorders known as the tauopathies which includes Alzheimer's disease. Precisely how and why Tau phosphorylation is increased in disease is not fully understood, nor how individual sites modify Tau function. Several groups have used the Drosophila visual system as an in vivo model to examine how the toxicity of Tau varies with phosphorylation status. This system relies on overexpression of Tau from transgenes but is susceptible to position effects altering expression and activity of the transgenes. We have refined the system by eliminating position effects through the use of site-specific integration. By standardising Tau expression levels we have been able to compare directly the toxicity of different isoforms of Tau and Tau point mutants that abolish important phosphorylation events. We have also examined the importance of human kinases in modulating Tau toxicity in vivo. We were able to confirm that human GSK3β phosphorylates Tau and increases toxicity but, unexpectedly, we identified that preventing phosphorylation of Ser404 is a protective event. When phosphorylation at this site is prevented, Tau toxicity in the Drosophila visual system is increased in the presence of GSK3β. Our data suggest that not all phosphorylation events on Tau are associated with toxicity.
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Affiliation(s)
- Giulia Povellato
- MRC Centre for Developmental Neurobiology, King's College London, New Hunt's House, Guy's Hospital Campus, London SE1 1UL, UK
| | - Richard I. Tuxworth
- MRC Centre for Developmental Neurobiology, King's College London, New Hunt's House, Guy's Hospital Campus, London SE1 1UL, UK
- School of Clinical and Experimental Medicine, University of Birmingham, The Medical School, Birmingham B15 2TT, UK
| | - Diane P. Hanger
- Department of Neuroscience, King's College London, Institute of Psychiatry, De Crespigny Park, London SE5 8AF, UK
| | - Guy Tear
- MRC Centre for Developmental Neurobiology, King's College London, New Hunt's House, Guy's Hospital Campus, London SE1 1UL, UK
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25
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Hyperphosphorylation of tau protein in the ipsilateral thalamus after focal cortical infarction in rats. Brain Res 2014; 1543:280-9. [DOI: 10.1016/j.brainres.2013.11.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 10/29/2013] [Accepted: 11/01/2013] [Indexed: 11/24/2022]
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26
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Erten-Lyons D, Woltjer R, Kaye J, Mattek N, Dodge HH, Green S, Tran H, Howieson DB, Wild K, Silbert LC. Neuropathologic basis of white matter hyperintensity accumulation with advanced age. Neurology 2013; 81:977-83. [PMID: 23935177 DOI: 10.1212/wnl.0b013e3182a43e45] [Citation(s) in RCA: 164] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
OBJECTIVE To determine which vascular pathology measure most strongly correlates with white matter hyperintensity (WMH) accumulation over time, and whether Alzheimer disease (AD) neuropathology correlates with WMH accumulation. METHODS Sixty-six older persons longitudinally followed as part of an aging study were included for having an autopsy and >1 MRI scan, with last MRI scan within 36 months of death. Mixed-effects models were used to examine the associations between longitudinal WMH accumulation and the following neuropathologic measures: myelin pallor, arteriolosclerosis, microvascular disease, microinfarcts, lacunar infarcts, large-vessel infarcts, atherosclerosis, neurofibrillary tangle rating, and neuritic plaque score. Each measure was included one at a time in the model, adjusted for duration of follow-up and age at death. A final model included measures showing an association with p < 0.1. RESULTS Mean age at death was 94.5 years (5.5 SD). In the final mixed-effects models, arteriolosclerosis, myelin pallor, and Braak score remained significantly associated with increased WMH accumulation over time. In post hoc analysis, we found that those with Braak score 5 or 6 were more likely to also have high atherosclerosis present compared with those with Braak score 1 or 2 (p = 0.003). CONCLUSION Accumulating white matter changes in advanced age are likely driven by small-vessel ischemic disease. Additionally, these results suggest a link between AD pathology and white matter integrity disruption. This may be due to wallerian degeneration secondary to neurodegenerative changes. Alternatively, a shared mechanism, for example ischemia, may lead to both vascular brain injury and neurodegenerative changes of AD. The observed correlation between atherosclerosis and AD pathology supports the latter.
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Affiliation(s)
- Deniz Erten-Lyons
- From the Department of Neurology (D.E.-L., J.K., L.C.S.), Veterans Affairs Medical Center, Portland, OR; and Departments of Neurology (D.E.-L., J.K., N.M., H.H.D., D.B.H., K.W., L.C.S.) and Pathology (R.W., S.G., H.T.), Oregon Health & Science University, Portland
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Novel multitarget ligand ITH33/IQM9.21 provides neuroprotection in in vitro and in vivo models related to brain ischemia. Neuropharmacology 2013; 67:403-11. [DOI: 10.1016/j.neuropharm.2012.12.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Revised: 11/27/2012] [Accepted: 12/03/2012] [Indexed: 01/05/2023]
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28
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Sagare AP, Bell RD, Zlokovic BV. Neurovascular dysfunction and faulty amyloid β-peptide clearance in Alzheimer disease. Cold Spring Harb Perspect Med 2012; 2:cshperspect.a011452. [PMID: 23028132 DOI: 10.1101/cshperspect.a011452] [Citation(s) in RCA: 172] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Neurovascular dysfunction is an integral part of Alzheimer disease (AD). Changes in the brain vascular system may contribute in a significant way to the onset and progression of cognitive decline and the development of a chronic neurodegenerative process associated with accumulation of amyloid β-peptide (Aβ) in brain and cerebral vessels in AD individuals and AD animal models. Here, we review the role of the neurovascular unit and molecular mechanisms in cerebral vascular cells behind the pathogenesis of AD. In particular, we focus on blood-brain barrier (BBB) dysfunction, decreased cerebral blood flow, and impaired vascular clearance of Aβ from brain. The data reviewed here support an essential role of the neurovascular and BBB mechanisms in AD pathogenesis.
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Affiliation(s)
- Abhay P Sagare
- Center for Neurodegenerative and Vascular Brain Disorders and Interdisciplinary Program in Dementia Research, Arthur Kornberg Medical Research Building, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, USA
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29
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Zlokovic BV. Neurovascular pathways to neurodegeneration in Alzheimer's disease and other disorders. Nat Rev Neurosci 2011; 12:723-38. [PMID: 22048062 DOI: 10.1038/nrn3114] [Citation(s) in RCA: 1966] [Impact Index Per Article: 151.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The neurovascular unit (NVU) comprises brain endothelial cells, pericytes or vascular smooth muscle cells, glia and neurons. The NVU controls blood-brain barrier (BBB) permeability and cerebral blood flow, and maintains the chemical composition of the neuronal 'milieu', which is required for proper functioning of neuronal circuits. Recent evidence indicates that BBB dysfunction is associated with the accumulation of several vasculotoxic and neurotoxic molecules within brain parenchyma, a reduction in cerebral blood flow, and hypoxia. Together, these vascular-derived insults might initiate and/or contribute to neuronal degeneration. This article examines mechanisms of BBB dysfunction in neurodegenerative disorders, notably Alzheimer's disease, and highlights therapeutic opportunities relating to these neurovascular deficits.
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Affiliation(s)
- Berislav V Zlokovic
- Department of Physiology and Biophysics, and Center for Neurodegeneration and Regeneration at the Zilkha Neurogenetic Institute, University of Southern California, Keck School of Medicine, 1501 San Pablo Street, Los Angeles, California 90089, USA.
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30
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Whiteman IT, Minamide LS, Goh DL, Bamburg JR, Goldsbury C. Rapid changes in phospho-MAP/tau epitopes during neuronal stress: cofilin-actin rods primarily recruit microtubule binding domain epitopes. PLoS One 2011; 6:e20878. [PMID: 21738590 PMCID: PMC3125162 DOI: 10.1371/journal.pone.0020878] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2011] [Accepted: 05/11/2011] [Indexed: 11/18/2022] Open
Abstract
Abnormal mitochondrial function is a widely reported contributor to neurodegenerative disease including Alzheimer's disease (AD), however, a mechanistic link between mitochondrial dysfunction and the initiation of neuropathology remains elusive. In AD, one of the earliest hallmark pathologies is neuropil threads comprising accumulated hyperphosphorylated microtubule-associated protein (MAP) tau in neurites. Rod-like aggregates of actin and its associated protein cofilin (AC rods) also occur in AD. Using a series of antibodies--AT270, AT8, AT100, S214, AT180, 12E8, S396, S404 and S422--raised against different phosphoepitopes on tau, we characterize the pattern of expression and re-distribution in neurites of these phosphoepitope labels during mitochondrial inhibition. Employing chick primary neuron cultures, we demonstrate that epitopes recognized by the monoclonal antibody 12E8, are the only species rapidly recruited into AC rods. These results were recapitulated with the actin depolymerizing drug Latrunculin B, which induces AC rods and a concomitant increase in the 12E8 signal measured on Western blot. This suggests that AC rods may be one way in which MAP redistribution and phosphorylation is influenced in neurons during mitochondrial stress and potentially in the early pathogenesis of AD.
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Affiliation(s)
- Ineka T. Whiteman
- The Brain and Mind Research Institute, University of Sydney, Sydney, Australia
- Bosch Institute, School of Medical Sciences, University of Sydney, Sydney, Australia
| | - Laurie S. Minamide
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, United States of America
| | - De Lian Goh
- The Brain and Mind Research Institute, University of Sydney, Sydney, Australia
- Bosch Institute, School of Medical Sciences, University of Sydney, Sydney, Australia
| | - James R. Bamburg
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Claire Goldsbury
- The Brain and Mind Research Institute, University of Sydney, Sydney, Australia
- Bosch Institute, School of Medical Sciences, University of Sydney, Sydney, Australia
- * E-mail:
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Wu G, Ju L, Jin T, Chen L, Shao L, Wang Y, Liu B. Local delivery of recombinant human bone morphogenetic protein-2 increases axonal regeneration and the expression of tau protein after facial nerve injury. J Int Med Res 2011; 38:1682-8. [PMID: 21309482 DOI: 10.1177/147323001003800513] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
This study explored the function and possible mechanism of bone morphogenetic protein-2 (BMP-2) in the healing of injured peripheral nerves in vivo. Rabbit facial nerves were injured by clamping and then treated with recombinant human BMP-2 (rhBMP-2) or phosphate-buffered saline (control) by injecting once during surgery and twice a day post-injury for 7 days. Facial nerve fragments within 5 mm of the clamping point were examined at different times post-surgery. Axon structures visualized by Bielschowsky staining were similar in experimental and control nerves 2 and 6 weeks post-injury. At 4 weeks post-injury, cross-section images of facial nerves showed that axons treated with rhBMP-2 were denser and thicker, and levels of tau protein were increased. It is concluded from these data that rhBMP-2 may affect injured facial nerve regeneration by inducing more neurons to return to embryonic patterns of tau gene expression.
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Affiliation(s)
- G Wu
- School of Stomatology, The Fourth Military Medical University, Xi'an, China
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Koike MA, Green KN, Blurton-Jones M, Laferla FM. Oligemic hypoperfusion differentially affects tau and amyloid-{beta}. THE AMERICAN JOURNAL OF PATHOLOGY 2010; 177:300-10. [PMID: 20472896 PMCID: PMC2893673 DOI: 10.2353/ajpath.2010.090750] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/02/2010] [Indexed: 11/20/2022]
Abstract
Decreased blood flow to the brain in humans is associated with altered Alzheimer's disease (AD)-related pathology, although the underlying mechanisms by which hypoperfusion influences AD neuropathology remains unknown. To try to address this question, we developed an oligemic model of cerebral hypoperfusion in the 3xTg-AD mouse model of AD. We bilaterally and transiently occluded the common carotid artery and then examined the molecular and cellular pathways by which hypoperfusion influenced tau and amyloid-beta proteins. We report the novel finding that a single, mild, transient hypoperfusion insult acutely increases Abeta levels by enhancing beta-secretase protein expression. In contrast, transient hypoperfusion markedly decreases total tau levels, coincident with activation of macroautophagy and ubiquitin-proteosome pathways. Furthermore, we find that oligemia results in a significant increase specifically in tau phosphorylated at serine(212) and threonine(214), a tau epitope associated with paired helical filaments in AD patients. Despite the mild and transient nature of this hypoperfusion injury, the pattern of decreased total tau, altered phosphorylated tau, and increased amyloid-beta persisted for several weeks postoligemia. Our study indicates that a single, mild, cerebral hypoperfusion event produces profound and long lasting effects on both tau and amyloid-beta. This finding may have implications for the pathogenesis of AD, as it indicates for the first time that total tau and amyloid-beta are differentially impacted by mild hypoperfusion.
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Affiliation(s)
- Maya A Koike
- Department of Neurobiology and Behavior, Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, 3212 Biological Sciences III, Irvine, CA 92697-4545, USA
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Zheng GQ, Wang XM, Wang Y, Wang XT. Tau as a potential novel therapeutic target in ischemic stroke. J Cell Biochem 2010; 109:26-9. [PMID: 19921714 DOI: 10.1002/jcb.22408] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Stroke is associated with high mortality and major disability burdens worldwide, but there are few effective and widely available therapies. Tau plays an important role in promoting microtubule assembly and stabilizing microtubule networks with phosphorylation regulating these functions. Based on the "ischemia-reperfusion theory" of Alzheimer's disease, some previous studies have focused on the relationship of tau and Alzheimer lesions in experimental brain ischemia. Thus, we hypothesize that the alterations in phosphorylation of tau are critical to microtubule dynamics and metabolism, and contribute to the pathophysiologic mechanisms during brain ischemia and/or reperfusion processes. We infer that regulation of phosphorylation of tau may be considered as a potential new therapeutic target in ischemic stroke.
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Affiliation(s)
- Guo-Qing Zheng
- Center of Neurology and Rehabilitation, The Second Affiliated Hospital of Wenzhou Medical College, Wenzhou 325027, China
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Abstract
Recent findings indicate that neurovascular dysfunction is an integral part of Alzheimer's disease (AD). Changes in the vascular system of the brain may significantly contribute to the onset and progression of dementia and to the development of a chronic neurodegenerative process. In contrast to the neurocentric view, which proposes that changes in chronic neurodegenerative disorders, including AD, can be attributed solely to neuronal disorder and neuronal dysfunction, the neurovascular concept proposes that dysfunction of non-neuronal neighboring cells and disintegration of neurovascular unit function may contribute to the pathogenesis of dementias in the elderly population, and understanding these processes will be crucial for the development of new therapeutic approaches to normalize both vascular and neuronal dysfunction. In this review, I discuss briefly the role of vascular factors and vascular disorder in AD, the link between cerebrovascular disorder and AD, the clearance hypothesis for AD, the role of RAGE (receptor for advanced glycation end products) and LRP (low density lipoprotein receptor related protein 1) in maintaining the levels of amyloid beta-peptide (Abeta) in the brain by controlling its transport across the blood-brain barrier (BBB), and the role of impaired vascular remodeling and cerebral blood flow dysregulation in the disease process. The therapeutic strategies based on new targets in the AD neurovascular pathway, such as RAGE and LRP receptors, and on a few selected genes implicated in AD neurovascular dysfunction (e.g., mesenchyme homeobox gene 2 and myocardin) are also discussed.
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Affiliation(s)
- Berislav V Zlokovic
- Center for Neurodegenerative and Vascular Brain Disorders, Departments of Neurosurgery, University of Rochester Medical School, Rochester, New York 14642, USA.
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Abstract
The blood-brain barrier (BBB) is a highly specialized brain endothelial structure of the fully differentiated neurovascular system. In concert with pericytes, astrocytes, and microglia, the BBB separates components of the circulating blood from neurons. Moreover, the BBB maintains the chemical composition of the neuronal "milieu," which is required for proper functioning of neuronal circuits, synaptic transmission, synaptic remodeling, angiogenesis, and neurogenesis in the adult brain. BBB breakdown, due to disruption of the tight junctions, altered transport of molecules between blood and brain and brain and blood, aberrant angiogenesis, vessel regression, brain hypoperfusion, and inflammatory responses, may initiate and/or contribute to a "vicious circle" of the disease process, resulting in progressive synaptic and neuronal dysfunction and loss in disorders such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, multiple sclerosis, and others. These findings support developments of new therapeutic approaches for chronic neurodegenerative disorders directed at the BBB and other nonneuronal cells of the neurovascular unit.
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