301
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Diem AK, Carare RO, Weller RO, Bressloff NW. A control mechanism for intra-mural peri-arterial drainage via astrocytes: How neuronal activity could improve waste clearance from the brain. PLoS One 2018; 13:e0205276. [PMID: 30286191 PMCID: PMC6171921 DOI: 10.1371/journal.pone.0205276] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 09/22/2018] [Indexed: 11/18/2022] Open
Abstract
The mechanisms behind the clearance of soluble waste from deep within the parenchyma of the brain remain unclear. Experimental evidence reveals that one pathway for clearance of waste, termed intra-mural peri-arterial drainage (IPAD), is the rapid drainage of interstitial fluid along basement membranes (BM) of the smooth muscle cells of cerebral arteries; failure of IPAD is closely associated with the pathology of Alzheimer's disease (AD), but its driving mechanism remains unclear. We have previously shown that arterial pulsations generated by the heart beat are not strong enough to drive IPAD. Here we present computational evidence for a mechanism for clearance of waste from the brain that is driven by functional hyperaemia, that is, the dilatation of cerebral arterioles as a consequence of increased nutrient demand from neurons. This mechanism is based on our model for the flow of fluid through the vascular BM. It accounts for clearance rates observed in mouse experiments, and aligns with pathological observations and recommendations to lower the individual risk of AD, such as mental and physical activity. Thus, our neurovascular hypothesis should act as the new working hypothesis for the driving force behind IPAD.
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Affiliation(s)
- Alexandra K. Diem
- Department of Computational Physiology, Simula Research Laboratory, 1364 Fornebu, Norway
- Computational Engineering and Design, Faculty of Engineering and the Environment, University of Southampton, Southampton Boldrewood Innovation Campus, Southampton, SO16 7QF, United Kingdom
- * E-mail:
| | - Roxana O. Carare
- Clinical Neurosciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, SO16 6YD, United Kingdom
| | - Roy O. Weller
- Neuropathology, Southampton General Hospital, Southampton, SO16 6YD, United Kingdom
| | - Neil W. Bressloff
- Computational Engineering and Design, Faculty of Engineering and the Environment, University of Southampton, Southampton Boldrewood Innovation Campus, Southampton, SO16 7QF, United Kingdom
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302
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Sweeney MD, Kisler K, Montagne A, Toga AW, Zlokovic BV. The role of brain vasculature in neurodegenerative disorders. Nat Neurosci 2018; 21:1318-1331. [PMID: 30250261 PMCID: PMC6198802 DOI: 10.1038/s41593-018-0234-x] [Citation(s) in RCA: 542] [Impact Index Per Article: 90.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Accepted: 07/20/2018] [Indexed: 12/12/2022]
Abstract
Adequate supply of blood and structural and functional integrity of blood vessels are key to normal brain functioning. On the other hand, cerebral blood flow shortfalls and blood-brain barrier dysfunction are early findings in neurodegenerative disorders in humans and animal models. Here we first examine molecular definition of cerebral blood vessels, as well as pathways regulating cerebral blood flow and blood-brain barrier integrity. Then we examine the role of cerebral blood flow and blood-brain barrier in the pathogenesis of Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, and multiple sclerosis. We focus on Alzheimer's disease as a platform of our analysis because more is known about neurovascular dysfunction in this disease than in other neurodegenerative disorders. Finally, we propose a hypothetical model of Alzheimer's disease biomarkers to include brain vasculature as a factor contributing to the disease onset and progression, and we suggest a common pathway linking brain vascular contributions to neurodegeneration in multiple neurodegenerative disorders.
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Affiliation(s)
- Melanie D Sweeney
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Kassandra Kisler
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Axel Montagne
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Arthur W Toga
- Laboratory of Neuro Imaging, Stevens Institute for Neuroimaging and Informatics, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Berislav V Zlokovic
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
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303
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Mullane K, Williams M. Alzheimer's disease (AD) therapeutics - 2: Beyond amyloid - Re-defining AD and its causality to discover effective therapeutics. Biochem Pharmacol 2018; 158:376-401. [PMID: 30273552 DOI: 10.1016/j.bcp.2018.09.027] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 09/24/2018] [Indexed: 12/25/2022]
Abstract
Compounds targeted for the treatment of Alzheimer's Disease (AD) have consistently failed in clinical trials despite evidence for target engagement and pharmacodynamic activity. This questions the relevance of compounds acting at current AD drug targets - the majority of which reflect the seminal amyloid and, to a far lesser extent, tau hypotheses - and limitations in understanding AD causality as distinct from general dementia. The preeminence of amyloid and tau led to many alternative approaches to AD therapeutics being ignored or underfunded to the extent that their causal versus contributory role in AD remains unknown. These include: neuronal network dysfunction; cerebrovascular disease; chronic, local or systemic inflammation involving the innate immune system; infectious agents including herpes virus and prion proteins; neurotoxic protein accumulation associated with sleep deprivation, circadian rhythm and glymphatic/meningeal lymphatic system and blood-brain-barrier dysfunction; metabolic related diseases including diabetes, obesity hypertension and hypocholesterolemia; mitochondrial dysfunction and environmental factors. As AD has become increasingly recognized as a multifactorial syndrome, a single treatment paradigm is unlikely to work in all patients. However, the biomarkers required to diagnose patients and parse them into mechanism/disease-based sub-groups remain rudimentary and unvalidated as do non-amyloid, non-tau translational animal models. The social and economic impact of AD is also discussed in the context of new FDA regulatory draft guidance and a proposed biomarker-based Framework (re)-defining AD and its stages as part of the larger landscape of treating dementia via the 2013 G8 initiative to identify a disease-modifying therapy for dementia/AD by 2025.
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Affiliation(s)
- Kevin Mullane
- Gladstone Institutes, San Francisco, CA, United States
| | - Michael Williams
- Department of Biological Chemistry and Pharmacology, College of Medicine, Ohio State University, Columbus, OH, United States.
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304
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Musen G, Tinsley LJ, Marcinkowski KA, Pober D, Sun JK, Khatri M, Huynh R, Lu A, King GL, Keenan HA. Cognitive Function Deficits Associated With Long-Duration Type 1 Diabetes and Vascular Complications. Diabetes Care 2018; 41:1749-1756. [PMID: 29871904 PMCID: PMC6054500 DOI: 10.2337/dc17-1955] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 05/06/2018] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Patients with type 1 diabetes now live long enough to experience cognitive decline. During middle age, they show mild cognitive deficits, but it is unknown whether severity increases with aging or whether cognitive profiles are similar to those of age-matched peers with and without diabetes. RESEARCH DESIGN AND METHODS We tested and compared cognition in 82 individuals with 50 or more years of type 1 diabetes (Medalists), 31 age-matched individuals with type 2 diabetes, and 30 age-matched control subjects without diabetes. Medical histories and biospecimens were collected. We also evaluated the association of complications with cognition in Medalists only. RESULTS Compared with control subjects, both individuals with type 1 diabetes and individuals with type 2 diabetes performed worse on immediate and delayed recall (P ≤ 0.002) and psychomotor speed in both hands (P ≤ 0.01) and showed a trend toward worse executive function (P = 0.05). In Medalists, cardiovascular disease was associated with decreased executive function and proliferative diabetic retinopathy with slower psychomotor speed. CONCLUSIONS Both patients with type 1 and patients with type 2 diabetes showed overall worse cognition than control subjects. Further, in Medalists, a relationship between complications and cognition was seen. Although both groups with diabetes showed similar deficit patterns, the underlying mechanisms may be different. Now that patients with type 1 diabetes are living longer, efforts should be made to evaluate cognition and to identify modifying behaviors to slow decline.
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Affiliation(s)
- Gail Musen
- Research Division, Joslin Diabetes Center, Boston, MA
- Harvard Medical School, Boston, MA
| | | | | | - David Pober
- Research Division, Joslin Diabetes Center, Boston, MA
- Harvard Medical School, Boston, MA
| | - Jennifer K Sun
- Research Division, Joslin Diabetes Center, Boston, MA
- Harvard Medical School, Boston, MA
| | - Maya Khatri
- Research Division, Joslin Diabetes Center, Boston, MA
| | - Richie Huynh
- Research Division, Joslin Diabetes Center, Boston, MA
| | - Annie Lu
- Research Division, Joslin Diabetes Center, Boston, MA
| | - George L King
- Research Division, Joslin Diabetes Center, Boston, MA
- Harvard Medical School, Boston, MA
| | - Hillary A Keenan
- Research Division, Joslin Diabetes Center, Boston, MA
- Harvard Medical School, Boston, MA
- Sanofi Genzyme, Cambridge, MA
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305
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Liu CY, Yang Y, Ju WN, Wang X, Zhang HL. Emerging Roles of Astrocytes in Neuro-Vascular Unit and the Tripartite Synapse With Emphasis on Reactive Gliosis in the Context of Alzheimer's Disease. Front Cell Neurosci 2018; 12:193. [PMID: 30042661 PMCID: PMC6048287 DOI: 10.3389/fncel.2018.00193] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Accepted: 06/14/2018] [Indexed: 01/09/2023] Open
Abstract
Astrocytes, which are five-fold more numerous than neurons in the central nervous system (CNS), are traditionally viewed to provide simple structural and nutritional supports for neurons and to participate in the composition of the blood brain barrier (BBB). In recent years, the active roles of astrocytes in regulating cerebral blood flow (CBF) and in maintaining the homeostasis of the tripartite synapse have attracted increasing attention. More importantly, astrocytes have been associated with the pathogenesis of Alzheimer's disease (AD), a major cause of dementia in the elderly. Although microglia-induced inflammation is considered important in the development and progression of AD, inflammation attributable to astrogliosis may also play crucial roles. A1 reactive astrocytes induced by inflammatory stimuli might be harmful by up-regulating several classical complement cascade genes thereby leading to chronic inflammation, while A2 induced by ischemia might be protective by up-regulating several neurotrophic factors. Here we provide a concise review of the emerging roles of astrocytes in the homeostasis maintenance of the neuro-vascular unit (NVU) and the tripartite synapse with emphasis on reactive astrogliosis in the context of AD, so as to pave the way for further research in this area, and to search for potential therapeutic targets of AD.
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Affiliation(s)
- Cai-Yun Liu
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Yu Yang
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Wei-Na Ju
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Xu Wang
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Hong-Liang Zhang
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
- Department of Life Sciences, The National Natural Science Foundation of China, Beijing, China
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306
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Carvalho C, Moreira PI. Oxidative Stress: A Major Player in Cerebrovascular Alterations Associated to Neurodegenerative Events. Front Physiol 2018; 9:806. [PMID: 30018565 PMCID: PMC6037979 DOI: 10.3389/fphys.2018.00806] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 06/08/2018] [Indexed: 12/19/2022] Open
Abstract
The brain is one of the most exquisite organs in the body with high metabolic demands, and requires a tight regulation of the surrounding environment. This tight control is exerted by the neurovascular unit (NVU) comprising different cell types, where endothelial cells play the commander-in-chief role. Thus, it is assumable that even slight perturbations in NVU might affect, in some cases irreversibly, brain homeostasis and health. In this line, recent findings support the two-hit vascular hypothesis for neurodegenerative conditions, where vascular dysfunction underlies the development of neurodegenerative diseases, such as Alzheimer’s disease (AD). Knowing that endothelial cells are rich in mitochondria and nicotinamide adenine dinucleotide phosphate (NADPH) oxidases, two major reactive oxygen species (ROS) sources, this review aims to gather information on how oxidative stress is in the front line of vascular alterations observed in brain aging and neurodegenerative conditions, particularly AD. Also, a brief discussion about the therapeutic strategies aimed to protect against cerebrovascular diseases is included.
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Affiliation(s)
- Cristina Carvalho
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
| | - Paula I Moreira
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Laboratory of Physiology, Faculty of Medicine, University of Coimbra, Coimbra, Portugal
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307
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The effects of cerebral amyloid angiopathy on integrity of the blood-brain barrier. Neurobiol Aging 2018; 70:70-77. [PMID: 30007166 DOI: 10.1016/j.neurobiolaging.2018.06.004] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Revised: 05/21/2018] [Accepted: 06/04/2018] [Indexed: 12/12/2022]
Abstract
Cerebral amyloid angiopathy (CAA), in which amyloid accumulates predominantly in the walls of arterioles and capillaries, is seen in most patients with Alzheimer disease (AD) and may contribute to compromise of blood-brain barrier (BBB) function seen in AD. We investigated the effects of CAA on BBB integrity by examining the expression of the endothelial marker CD31, basement membrane protein collagen IV (COL4), tight junction protein claudin-5, and fibrinogen, a marker of BBB leakage, by immunohistochemistry in the occipital cortex of autopsy brains with AD and capillary CAA (CAA type 1; n = 8), AD with noncapillary CAA (CAA type 2; n = 10), and AD without CAA (n = 7) compared with elderly controls (n = 10). Given the difference in pathogenesis of capillary and noncapillary CAA, we hypothesize that features of BBB breakdown are observed only in capillary CAA. We found decreased expression of CD31 in AD subjects with CAA types 1 and 2 compared with AD without CAA and an increase in COL4 in AD without CAA compared with controls. Furthermore, there was increased immunoreactivity for fibrinogen in AD with CAA type 1 compared with controls. These findings suggest that capillary CAA is associated with morphologic and possibly physiologic alterations of the neurovascular unit and increased BBB permeability in AD.
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308
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Kisler K, Lazic D, Sweeney MD, Plunkett S, Khatib ME, Vinogradov SA, Boas DA, Sakadžić S, Zlokovic BV. In vivo imaging and analysis of cerebrovascular hemodynamic responses and tissue oxygenation in the mouse brain. Nat Protoc 2018; 13:1377-1402. [PMID: 29844521 PMCID: PMC6402338 DOI: 10.1038/nprot.2018.034] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cerebrovascular dysfunction has an important role in the pathogenesis of multiple brain disorders. Measurement of hemodynamic responses in vivo can be challenging, particularly as techniques are often not described in sufficient detail and vary between laboratories. We present a set of standardized in vivo protocols that describe high-resolution two-photon microscopy and intrinsic optical signal (IOS) imaging to evaluate capillary and arteriolar responses to a stimulus, regional hemodynamic responses, and oxygen delivery to the brain. The protocol also describes how to measure intrinsic NADH fluorescence to understand how blood O2 supply meets the metabolic demands of activated brain tissue, and to perform resting-state absolute oxygen partial pressure (pO2) measurements of brain tissue. These methods can detect cerebrovascular changes at far higher resolution than MRI techniques, although the optical nature of these techniques limits their achievable imaging depths. Each individual procedure requires 1-2 h to complete, with two to three procedures typically performed per animal at a time. These protocols are broadly applicable in studies of cerebrovascular function in healthy and diseased brain in any of the existing mouse models of neurological and vascular disorders. All these procedures can be accomplished by a competent graduate student or experienced technician, except the two-photon measurement of absolute pO2 level, which is better suited to a more experienced, postdoctoral-level researcher.
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Affiliation(s)
- Kassandra Kisler
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089
| | - Divna Lazic
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089
- Department of Neurobiology, Institute for Biological Research, University of Belgrade, Belgrade, Republic of Serbia
| | - Melanie D. Sweeney
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089
| | - Shane Plunkett
- Departments of Biochemistry and Biophysics and of Chemistry, University of Pennsylvania, Philadelphia, PA 19104
| | - Mirna El Khatib
- Departments of Biochemistry and Biophysics and of Chemistry, University of Pennsylvania, Philadelphia, PA 19104
| | - Sergei A. Vinogradov
- Departments of Biochemistry and Biophysics and of Chemistry, University of Pennsylvania, Philadelphia, PA 19104
| | - David A. Boas
- Optics Division, MGH/HMS/MIT Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 149 13th Street, Charlestown, MA 02129
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215
| | - Sava Sakadžić
- Optics Division, MGH/HMS/MIT Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 149 13th Street, Charlestown, MA 02129
| | - Berislav V. Zlokovic
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089
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309
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Sen A, Hongpaisan J. Hippocampal microvasculature changes in association with oxidative stress in Alzheimer's disease. Free Radic Biol Med 2018; 120:192-203. [PMID: 29572097 DOI: 10.1016/j.freeradbiomed.2018.03.034] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 03/14/2018] [Accepted: 03/17/2018] [Indexed: 12/13/2022]
Abstract
Vascular endothelial dysfunction is a primary phenotype of aging, and microvascular (MV) lesion is mainly associated with Alzheimer's disease (AD). Here we have studied the correlation of MV wall thickness and CA1 pyramidal neuronal pathology in autopsy-confirmed AD brains. Both hyaline (h-MV) and increased cell number (c-MV) associated MV wall thickening was found in age-matched control (AC) hippocampus without significant change in Aβ level (Braak stages 0-III). AC neurons neighboring the h-MV showed lower levels of oxidative DNA/RNA damage and Aβ precursor protein (APP), while the neurons around c-MV showed higher oxidative DNA/RNA damage with increased APP expression. Neurons in AC hippocampus without MV wall thickening (thin wall) showed increased DNA/RNA damage and APP levels compared to AC cases with h-MV and c-MV walls. In the AD hippocampus neurons neighboring h-MV walls showed increased levels of Aβ and decreased number of dendritic spines (at Braak stages IV-VI). C-MV neighboring neurons in the AD cases showed higher levels of DNA/RNA damage with increased APP at stages II - III, followed by lower levels of oxidative DNA/RNA damage, decreased APP and increased Aβ levels with loss of dendritic spines at stages IV-VI. Prolonged treatment of primary human fetal hippocampal neurons with tert-butyl hydroperoxide (TBHP) induced oxidative DNA damage with a sustained increase in APP. Aβ increased rapidly and then decreased overtime. Short-term TBHP treated neurons showed lower levels of superoxide (O2• -) without significant DNA damage. Short-term TBHP treatment induced a gradual decrease in APP but an increase in Aβ levels over time. In conclusion this study indicates that AD hippocampus at Braak stages II-III are characterized by strong oxidative DNA/RNA damage with increased APP in neurons associated with c-MV, while stages IV-VI are characterized by a slow increase in Aβ in neurons neighboring both h-MV and c-MV.
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Affiliation(s)
- Abhik Sen
- Center for Neurodegenerative Diseases, Blanchette Rockefeller Neurosciences Institute, West Virginia University, Morgantown, WV, 26505, USA
| | - Jarin Hongpaisan
- Center for Neurodegenerative Diseases, Blanchette Rockefeller Neurosciences Institute, West Virginia University, Morgantown, WV, 26505, USA.
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310
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Raja R, Rosenberg GA, Caprihan A. MRI measurements of Blood-Brain Barrier function in dementia: A review of recent studies. Neuropharmacology 2018; 134:259-271. [PMID: 29107626 PMCID: PMC6044415 DOI: 10.1016/j.neuropharm.2017.10.034] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2017] [Revised: 10/24/2017] [Accepted: 10/26/2017] [Indexed: 12/26/2022]
Abstract
Blood-brain barrier (BBB) separates the systemic circulation and the brain, regulating transport of most molecules to protect the brain microenvironment. Multiple structural and functional components preserve the integrity of the BBB. Several imaging modalities are available to study disruption of the BBB. However, the subtle changes in BBB leakage that occurs in vascular cognitive impairment and Alzheimer's disease have been less well studied. Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) is the most widely adopted non-invasive imaging technique for evaluating BBB breakdown. It is used as a significant marker for a wide variety of diseases with large permeability leaks, such as brain tumors and multiple sclerosis, to more subtle disruption in chronic vascular disease and dementia. DCE-MRI analysis of BBB includes both model-free parameters and quantitative parameters using pharmacokinetic modelling. We review MRI studies of BBB breakdown in dementia. The challenges in measuring subtle BBB changes and the state of the art techniques are initially examined. Subsequently, a systematic review comparing methodologies from recent in-vivo MRI studies is presented. Various factors related to subtle BBB permeability measurement such as DCE-MRI acquisition parameters, arterial input assessment, T1 mapping and data analysis methods are reviewed with the focus on finding the optimal technique. Finally, the reported BBB permeability values in dementia are compared across different studies and across various brain regions. We conclude that reliable measurement of low-level BBB permeability across sites remains a difficult problem and a standardization of the methodology for both data acquisition and quantitative analysis is required. This article is part of the Special Issue entitled 'Cerebral Ischemia'.
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Affiliation(s)
| | - Gary A Rosenberg
- Department of Neurology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
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311
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Chen H, Su F, Ye Q, Wang Z, Shu H, Bai F. The Dose-Dependent Effects of Vascular Risk Factors on Dynamic Compensatory Neural Processes in Mild Cognitive Impairment. Front Aging Neurosci 2018; 10:131. [PMID: 29867442 PMCID: PMC5951955 DOI: 10.3389/fnagi.2018.00131] [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: 12/13/2017] [Accepted: 04/20/2018] [Indexed: 01/14/2023] Open
Abstract
Background/Objectives: Mild cognitive impairment (MCI) has been associated with risk for Alzheimer's Disease (AD). Previous investigations have suggested that vascular risk factors (VRFs) were associated with cognitive decline and AD pathogenesis, and the intervention of VRFs may be a possible way to prevent dementia. However, in MCI, little is known about the potential impacts of VRFs on neural networks and their neural substrates, which may be a neuroimaging biomarker of the disease progression. Methods: 128 elderly Han Chinese participants (67 MCI subjects and 61 matched normal elderly) with or without VRFs (hypertension, diabetes mellitus, hypercholesterolemia, smoking and alcohol drinking) underwent the resting-state functional magnetic resonance imaging (fMRI) and neuropsychological tests. We obtained the default mode network (DMN) to identify alterations in MCI with the varying number of the VRF and analyzed the significant correlation with behavioral performance. Results: The effects of VRF on the DMN were primarily in bilateral dorsolateral prefrontal cortex (DLPFC) (i.e., middle frontal gyrus). Normal elderly showed the gradually increased functional activity of DLPFC, while a fluctuant activation of DLPFC was displayed in MCI with the growing number of the VRF. Interestingly, the left DLPFC further displayed significantly dynamic correlation with executive function as the variation of VRF loading. Initial level of compensation was observed in normal aging and none-vascular risk factor (NVRF) MCI, while these compensatory neural processes were suppressed in One-VRF MCI and were subsequently re-aroused in Over-One-VRF MCI. Conclusions: These findings suggested that the dose-dependent effects of VRF on DLPFC were highlighted in MCI, and the dynamic compensatory neural processes that fluctuated along with variations of VRF loading could be key role in the progression of MCI.
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Affiliation(s)
- Haifeng Chen
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, China
| | - Fan Su
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, China
| | - Qing Ye
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, China
| | - Zan Wang
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, China
| | - Hao Shu
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, China
| | - Feng Bai
- Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, China
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312
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Katzorke A, Zeller JBM, Müller LD, Lauer M, Polak T, Deckert J, Herrmann MJ. Decreased hemodynamic response in inferior frontotemporal regions in elderly with mild cognitive impairment. Psychiatry Res Neuroimaging 2018; 274:11-18. [PMID: 29472145 DOI: 10.1016/j.pscychresns.2018.02.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 01/15/2018] [Accepted: 02/09/2018] [Indexed: 02/01/2023]
Abstract
The verbal fluency task (VFT) is a well-established cognitive marker for mild cognitive impairment (MCI) in the prodromal stage of Alzheimer´s dementia (AD). The behavioral VFT performance of patients allows the prediction of dementia two years later. But effective compensatory mechanism might cover or reduce the predictive value of the VFT. Therefore the aim of this study is to measure the hemodynamic response during VFT in patients with mild cognitive impairment (MCI) to establish the hemodynamic response during the VFT as a screening instrument for the prediction of dementia. One method which allows measuring the hemodynamic response during speech production without severe problems with moving artifacts like in functional magnetic resonance imaging (fMRI) is the functional near-infrared spectroscopy (fNIRS). It is optimal as a screening instrument, as it is easy to apply and without any contraindications. In this study we assessed the hemodynamic response in prefrontal and temporal regions in patients with MCI as well as matched healthy controls with fNIRS. We found a decreased hemodynamic response in the inferior frontotemporal cortex for the MCI group. Our results indicate that a frontotemporal decreased hemodynamic response could serve as a diagnostic biomarker for dementia.
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Affiliation(s)
- Andrea Katzorke
- Department of Psychiatry, Psychosomatics and Psychotherapy, University Hospital Würzburg, Margarete-Höppel-Platz 1, D - 97080 Würzburg, Germany.
| | - Julia B M Zeller
- Department of Psychiatry, Psychosomatics and Psychotherapy, University Hospital Würzburg, Margarete-Höppel-Platz 1, D - 97080 Würzburg, Germany
| | - Laura D Müller
- Department of Psychiatry, Psychosomatics and Psychotherapy, University Hospital Würzburg, Margarete-Höppel-Platz 1, D - 97080 Würzburg, Germany
| | - Martin Lauer
- Department of Psychiatry, Psychosomatics and Psychotherapy, University Hospital Würzburg, Margarete-Höppel-Platz 1, D - 97080 Würzburg, Germany
| | - Thomas Polak
- Department of Psychiatry, Psychosomatics and Psychotherapy, University Hospital Würzburg, Margarete-Höppel-Platz 1, D - 97080 Würzburg, Germany
| | - Jürgen Deckert
- Department of Psychiatry, Psychosomatics and Psychotherapy, University Hospital Würzburg, Margarete-Höppel-Platz 1, D - 97080 Würzburg, Germany
| | - Martin J Herrmann
- Department of Psychiatry, Psychosomatics and Psychotherapy, University Hospital Würzburg, Margarete-Höppel-Platz 1, D - 97080 Würzburg, Germany
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313
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Lattanzi S, Brigo F, Vernieri F, Silvestrini M. Visit-to-visit variability in blood pressure and Alzheimer's disease. J Clin Hypertens (Greenwich) 2018; 20:918-924. [PMID: 29693801 DOI: 10.1111/jch.13290] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 03/07/2018] [Accepted: 03/11/2018] [Indexed: 12/20/2022]
Abstract
Alzheimer's disease is the most common type of dementia and one of the leading sources of disability and dependency in the elderly. Given the limited treatment options, understanding the role of modifiable risk factors implied in the disease pathogenesis is a worthwhile endeavor to limit its global burden. Recently, the variability of blood pressure has been suggested to be a significant determinant of brain alterations and a potential therapeutic target. The aim of this article is to review the clinical evidence on the association between visit-to-visit blood pressure variability and Alzheimer's disease, highlight the underlying mechanisms, and suggest future implications.
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Affiliation(s)
- Simona Lattanzi
- Neurological Clinic, Department of Experimental and Clinical Medicine, Marche Polytechnic University, Ancona, Italy
| | - Francesco Brigo
- Department of Neuroscience, Biomedicine and Movement Science, University of Verona, Verona, Italy.,Division of Neurology, "Franz Tappeiner" Hospital, Merano, BZ, Italy
| | | | - Mauro Silvestrini
- Neurological Clinic, Department of Experimental and Clinical Medicine, Marche Polytechnic University, Ancona, Italy
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314
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Jou YT. Dental deafferentation and brain damage: A review and a hypothesis. Kaohsiung J Med Sci 2018; 34:231-237. [PMID: 29655412 DOI: 10.1016/j.kjms.2018.01.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 12/07/2017] [Accepted: 01/12/2018] [Indexed: 01/04/2023] Open
Abstract
In the last few decades, neurobiological and human brain imaging research have greatly advanced our understanding of brain mechanisms that support perception and memory, as well as their function in daily activities. Knowledge of the neurobiological mechanisms behind the deafferentation of stomatognathic systems has also expanded greatly in recent decades. In particular, current studies reveal that the peripheral deafferentations of stomatognathic systems may be projected globally into the central nervous system (CNS) and become an associated critical factor in triggering and aggravating neurodegenerative diseases. This review explores basic neurobiological mechanisms associated with the deafferentation of stomatognathic systems. Further included is a discussion on tooth loss and other dental deafferentation (DD) mechanisms, with a focus on dental and masticatory apparatuses associated with brain functions and which may underlie the changes observed in the aging brain. A new hypothesis is presented where DD and changes in the functionality of teeth and the masticatory apparatus may cause brain damage as a result of altered cerebral circulation and dysfunctional homeostasis. Furthermore, multiple recurrent reorganizations of the brain may be a triggering or contributing risk factor in the onset and progression of neurodegenerative conditions such as Alzheimer's disease (AD). A growing understanding of the association between DD and brain aging may lead to solutions in treating and preventing cognitive decline and neurodegenerative diseases.
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Affiliation(s)
- Yi-Tai Jou
- Department of Endodontics School of Dental Medicine University of Pennsylvania Philadelphia, Pennsylvania, USA.
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315
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Beishon L, Haunton VJ, Panerai RB, Robinson TG. Cerebral Hemodynamics in Mild Cognitive Impairment: A Systematic Review. J Alzheimers Dis 2018; 59:369-385. [PMID: 28671118 DOI: 10.3233/jad-170181] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND The incidence of dementia is projected to rise over the coming decades, but with no sensitive diagnostic tests available. Vascular pathology precedes the deposition of amyloid and is an attractive early target. OBJECTIVE The aim of this review was to investigate the use of cerebral hemodynamics and oxygenation as a novel biomarker for mild cognitive impairment (MCI), focusing on transcranial Doppler ultrasonography (TCD) and near-infrared spectroscopy (NIRS). METHODS 2,698 articles were identified from Medline, Embase, PsychINFO, and Web of Science databases. 306 articles were screened and quality assessed independently by two reviewers; 26 met the inclusion criteria. Meta-analyses were performed for each marker with two or more studies and limited heterogeneity. RESULTS Eleven studies were TCD, 8 NIRS, 5 magnetic resonance imaging, and 2 positron/single photon emission tomography. Meta-analyses showed reduced tissue oxygenation index, cerebral blood flow and velocity, with higher pulsatility index, phase and cerebrovascular resistance in MCI compared to controls. The majority of studies found reduced CO2 reactivity in MCI, with mixed findings in neuroactivation studies. CONCLUSION Despite small sample sizes and heterogeneity, meta-analyses demonstrate clear abnormalities in cerebral hemodynamic and oxygenation parameters, even at an early stage of cognitive decline. Further work is required to investigate the use of cerebral hemodynamic and oxygenation parameters as a sensitive biomarker for dementia.
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Affiliation(s)
- Lucy Beishon
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | - Victoria J Haunton
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK.,NIHR Biomedical Research Unit in Cardiovascular Disease, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, UK
| | - Ronney B Panerai
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK.,NIHR Biomedical Research Unit in Cardiovascular Disease, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, UK
| | - Thompson G Robinson
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK.,NIHR Biomedical Research Unit in Cardiovascular Disease, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, UK
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316
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Potjewyd G, Moxon S, Wang T, Domingos M, Hooper NM. Tissue Engineering 3D Neurovascular Units: A Biomaterials and Bioprinting Perspective. Trends Biotechnol 2018; 36:457-472. [DOI: 10.1016/j.tibtech.2018.01.003] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 01/05/2018] [Accepted: 01/08/2018] [Indexed: 12/14/2022]
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317
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Van Skike CE, Jahrling JB, Olson AB, Sayre NL, Hussong SA, Ungvari Z, Lechleiter JD, Galvan V. Inhibition of mTOR protects the blood-brain barrier in models of Alzheimer's disease and vascular cognitive impairment. Am J Physiol Heart Circ Physiol 2018; 314:H693-H703. [PMID: 29351469 PMCID: PMC5966773 DOI: 10.1152/ajpheart.00570.2017] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 11/29/2017] [Accepted: 12/13/2017] [Indexed: 01/05/2023]
Abstract
An intact blood-brain barrier (BBB) limits entry of proinflammatory and neurotoxic blood-derived factors into the brain parenchyma. The BBB is damaged in Alzheimer's disease (AD), which contributes significantly to the progression of AD pathologies and cognitive decline. However, the mechanisms underlying BBB breakdown in AD remain elusive, and no interventions are available for treatment or prevention. We and others recently established that inhibition of the mammalian/mechanistic target of rapamycin (mTOR) pathway with rapamycin yields significant neuroprotective effects, improving cerebrovascular and cognitive function in mouse models of AD. To test whether mTOR inhibition protects the BBB in neurological diseases of aging, we treated hAPP(J20) mice modeling AD and low-density lipoprotein receptor-null (LDLR-/-) mice modeling vascular cognitive impairment with rapamycin. We found that inhibition of mTOR abrogates BBB breakdown in hAPP(J20) and LDLR-/- mice. Experiments using an in vitro BBB model indicated that mTOR attenuation preserves BBB integrity through upregulation of specific tight junction proteins and downregulation of matrix metalloproteinase-9 activity. Together, our data establish mTOR activity as a critical mediator of BBB breakdown in AD and, potentially, vascular cognitive impairment and suggest that rapamycin and/or rapalogs could be used for the restoration of BBB integrity. NEW & NOTEWORTHY This report establishes mammalian/mechanistic target of rapamycin as a critical mediator of blood-brain barrier breakdown in models of Alzheimer's disease and vascular cognitive impairment and suggests that drugs targeting the target of rapamycin pathway could be used for the restoration of blood-brain barrier integrity in disease states.
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MESH Headings
- Alzheimer Disease/drug therapy
- Alzheimer Disease/enzymology
- Alzheimer Disease/pathology
- Alzheimer Disease/psychology
- Animals
- Behavior, Animal
- Blood-Brain Barrier/drug effects
- Blood-Brain Barrier/enzymology
- Blood-Brain Barrier/pathology
- Cell Line
- Cognition
- Dementia, Vascular/drug therapy
- Dementia, Vascular/enzymology
- Dementia, Vascular/pathology
- Dementia, Vascular/psychology
- Disease Models, Animal
- Female
- Male
- Matrix Metalloproteinase 9/metabolism
- Mechanistic Target of Rapamycin Complex 1/metabolism
- Mice, Inbred C57BL
- Mice, Knockout
- Protein Kinase Inhibitors/pharmacology
- Receptors, LDL/deficiency
- Receptors, LDL/genetics
- Sirolimus/pharmacology
- TOR Serine-Threonine Kinases/antagonists & inhibitors
- TOR Serine-Threonine Kinases/metabolism
- Tight Junction Proteins/metabolism
- Tight Junctions/drug effects
- Tight Junctions/enzymology
- Tight Junctions/pathology
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Affiliation(s)
- Candice E Van Skike
- Department of Cellular and Integrative Physiology and Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio , San Antonio, Texas
| | - Jordan B Jahrling
- Department of Cellular and Integrative Physiology and Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio , San Antonio, Texas
| | - Angela B Olson
- Department of Cellular and Integrative Physiology and Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio , San Antonio, Texas
| | - Naomi L Sayre
- Department of Neurosurgery, University of Texas Health San Antonio , San Antonio, Texas
- Department of Veterans Affairs, South Texas Veterans Health Care System, San Antonio, Texas
| | - Stacy A Hussong
- Department of Cellular and Integrative Physiology and Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio , San Antonio, Texas
- Department of Veterans Affairs, South Texas Veterans Health Care System, San Antonio, Texas
| | - Zoltan Ungvari
- Department of Geriatric Medicine and Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center , Oklahoma City, Oklahoma
| | - James D Lechleiter
- Department of Cellular and Structural Biology, South Texas Research Facility Neuroscience Center, University of Texas Health San Antonio, San Antonio, Texas
| | - Veronica Galvan
- Department of Cellular and Integrative Physiology and Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio , San Antonio, Texas
- Department of Veterans Affairs, South Texas Veterans Health Care System, San Antonio, Texas
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318
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D'Arrigo JS. Targeting Early Dementia: Using Lipid Cubic Phase Nanocarriers to Cross the Blood⁻Brain Barrier. Biomimetics (Basel) 2018; 3:E4. [PMID: 31105226 PMCID: PMC6352688 DOI: 10.3390/biomimetics3010004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 02/21/2018] [Accepted: 03/06/2018] [Indexed: 12/14/2022] Open
Abstract
Over the past decades, a frequent co-morbidity of cerebrovascular pathology and Alzheimer's disease has been observed. Numerous published studies indicate that the preservation of a healthy cerebrovascular endothelium can be an important therapeutic target. By incorporating the appropriate drug(s) into biomimetic (lipid cubic phase) nanocarriers, one obtains a multitasking combination therapeutic, which targets certain cell surface scavenger receptors, mainly class B type I (i.e., SR-BI), and crosses the blood⁻brain barrier. This targeting allows for various cell types related to Alzheimer's to be simultaneously searched out for localized drug treatment in vivo.
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319
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Bors L, Tóth K, Tóth EZ, Bajza Á, Csorba A, Szigeti K, Máthé D, Perlaki G, Orsi G, Tóth GK, Erdő F. Age-dependent changes at the blood-brain barrier. A Comparative structural and functional study in young adult and middle aged rats. Brain Res Bull 2018. [PMID: 29522862 DOI: 10.1016/j.brainresbull.2018.03.001] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Decreased beta-amyloid clearance in Alzheimer's disease and increased blood-brain barrier permeability in aged subjects have been reported in several articles. However, morphological and functional characterization of blood-brain barrier and its membrane transporter activity have not been described in physiological aging yet. The aim of our study was to explore the structural changes in the brain microvessels and possible functional alterations of P-glycoprotein at the blood-brain barrier with aging. Our approach included MR imaging for anatomical orientation in middle aged rats, electronmicroscopy and immunohistochemistry to analyse the alterations at cellular level, dual or triple-probe microdialysis and SPECT to test P-glycoprotein functionality in young and middle aged rats. Our results indicate that the thickness of basal lamina increases, the number of tight junctions decreases and the size of astrocyte endfeet extends with advanced age. On the basis of microdialysis and SPECT results the P-gp function is reduced in old rats. With our multiparametric approach a complex regulation can be suggested which includes elements leading to increased permeability of blood-brain barrier by enhanced paracellular and transcellular transport, and factors working against it. To verify the role of P-gp pumps in brain aging further studies are warranted.
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Affiliation(s)
- Luca Bors
- Pázmány Péter Catholic University, Faculty of Information Technology and Bionics, Práter u. 50a, H-1083 Budapest
| | - Kinga Tóth
- Hungarian Academy of Sciences, Institute of Cognitive Neuroscience and Psychology, Magyar tudósok körútja 2. H-1117 Budapest
| | - Estilla Zsófia Tóth
- Hungarian Academy of Sciences, Institute of Cognitive Neuroscience and Psychology, Magyar tudósok körútja 2. H-1117 Budapest
| | - Ágnes Bajza
- Pázmány Péter Catholic University, Faculty of Information Technology and Bionics, Práter u. 50a, H-1083 Budapest
| | - Attila Csorba
- University of Szeged, Faculty of Pharmacy, Deparment of Pharmacognosy, Eötvös u. 6, H-6720 Szeged
| | - Krisztián Szigeti
- Semmelweis University, Faculty of Medicine, Department of Biophysics and Radiation Biology, Tűzoltó u. 37-47, H-1094 Budapest
| | - Domokos Máthé
- Semmelweis University, Faculty of Medicine, Department of Biophysics and Radiation Biology, Tűzoltó u. 37-47, H-1094 Budapest,; CROmed Translational Research Ltd. Budapest
| | - Gábor Perlaki
- MTA-PTE Clinical Neuroscience MR Research Group, Ret u. 2, H-7623 Pecs, Hungary; Department of Neurosurgery, University of Pecs, Medical School, Ret u. 2, H-7623 Pecs, Hungary
| | - Gergely Orsi
- MTA-PTE Clinical Neuroscience MR Research Group, Ret u. 2, H-7623 Pecs, Hungary; Department of Neurosurgery, University of Pecs, Medical School, Ret u. 2, H-7623 Pecs, Hungary
| | - Gábor K Tóth
- Department of Medical Chemistry, Faculty of Medicine, University of Szeged, Dóm tér 8, H-6720, Szeged, Hungary
| | - Franciska Erdő
- Pázmány Péter Catholic University, Faculty of Information Technology and Bionics, Práter u. 50a, H-1083 Budapest.
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320
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Amtul Z, Yang J, Nikolova S, Lee TY, Bartha R, Cechetto DF. The Dynamics of Impaired Blood-Brain Barrier Restoration in a Rat Model of Co-morbid Injury. Mol Neurobiol 2018; 55:8071-8083. [PMID: 29508280 DOI: 10.1007/s12035-018-0904-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 01/10/2018] [Indexed: 12/31/2022]
Abstract
Defect in brain microperfusion is increasingly recognized as an antecedent event to Alzheimer's disease (AD) and ischemia. Nevertheless, studies on the role of impaired microperfusion as a pathological trigger to neuroinflammation, Aβ deposition as well as blood-brain barrier (BBB) disruption, and the etiological link between AD and ischemia are lacking. In this study, we employ in vivo sequential magnetic resonance imaging (MRI) and computed tomography (CT) imaging in a co-morbid rat model of β-amyloid toxicity (Aβ) and ischemia (ET1) with subsequent histopathology of striatal lesion core and penumbra at 1, 7, and 28 days post injury. Within 24 h, cerebral injury resulted in increased BBB permeability due to the dissolution of β-dystroglycan (β-DG) and basement membrane laminin by active matrix metalloproteinase9 (MMP9). As a result, net flow of circulating IgG down a hydrostatic gradient into the parenchyma led to vasogenic edema and impaired perfusion, thus increasing the apparent hyperintensity in true fast imaging with steady-state free precession (true FISP) imaging and acute hypoperfusion in CT. This was followed by a slow recruitment of reactive astroglia to the affected brain and depolarization of aquaporin4 (AQP4) expression resulting in cytotoxic edema-in an attempt to resolve vasogenic edema. On d28, functional BBB was restored in ET1 rats as observed by astrocytic MMP9 release, β-DG stabilization, and new vessel formation. This was confirmed by reduced hyperintensity on true FISP imaging and normalized cerebral blood flow in CT. While, Aβ toxicity alone was not detrimental enough, Aβ+ET1 rats showed delayed differential expression of MMP9, late recruitment of astroglial cells, protracted loss of AQP4 depolarization, and thus delayed BBB restoration and cerebral perfusion.
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Affiliation(s)
- Zareen Amtul
- Department of Anatomy and Cell Biology, University of Western Ontario, London, ON, N6A 5C1, Canada.
| | - Jun Yang
- Centre for Functional and Metabolic Mapping, Robarts Research Institute, University of Western Ontario, London, ON, N6A 5K7, Canada
| | - Simona Nikolova
- Centre for Functional and Metabolic Mapping, Robarts Research Institute, University of Western Ontario, London, ON, N6A 5K7, Canada
| | - Ting-Yim Lee
- Centre for Functional and Metabolic Mapping, Robarts Research Institute, University of Western Ontario, London, ON, N6A 5K7, Canada
| | - Robert Bartha
- Centre for Functional and Metabolic Mapping, Robarts Research Institute, University of Western Ontario, London, ON, N6A 5K7, Canada.,Department of Medical Biophysics, University of Western Ontario, London, ON, N6A 3K7, Canada
| | - David F Cechetto
- Department of Anatomy and Cell Biology, University of Western Ontario, London, ON, N6A 5C1, Canada
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321
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Sweeney MD, Sagare AP, Zlokovic BV. Blood-brain barrier breakdown in Alzheimer disease and other neurodegenerative disorders. Nat Rev Neurol 2018; 14:133-150. [PMID: 29377008 PMCID: PMC5829048 DOI: 10.1038/nrneurol.2017.188] [Citation(s) in RCA: 1617] [Impact Index Per Article: 269.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The blood-brain barrier (BBB) is a continuous endothelial membrane within brain microvessels that has sealed cell-to-cell contacts and is sheathed by mural vascular cells and perivascular astrocyte end-feet. The BBB protects neurons from factors present in the systemic circulation and maintains the highly regulated CNS internal milieu, which is required for proper synaptic and neuronal functioning. BBB disruption allows influx into the brain of neurotoxic blood-derived debris, cells and microbial pathogens and is associated with inflammatory and immune responses, which can initiate multiple pathways of neurodegeneration. This Review discusses neuroimaging studies in the living human brain and post-mortem tissue as well as biomarker studies demonstrating BBB breakdown in Alzheimer disease, Parkinson disease, Huntington disease, amyotrophic lateral sclerosis, multiple sclerosis, HIV-1-associated dementia and chronic traumatic encephalopathy. The pathogenic mechanisms by which BBB breakdown leads to neuronal injury, synaptic dysfunction, loss of neuronal connectivity and neurodegeneration are described. The importance of a healthy BBB for therapeutic drug delivery and the adverse effects of disease-initiated, pathological BBB breakdown in relation to brain delivery of neuropharmaceuticals are briefly discussed. Finally, future directions, gaps in the field and opportunities to control the course of neurological diseases by targeting the BBB are presented.
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Affiliation(s)
- Melanie D Sweeney
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, 1501 San Pablo Street, Los Angeles, California 90089, USA
| | - Abhay P Sagare
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, 1501 San Pablo Street, Los Angeles, California 90089, USA
| | - Berislav V Zlokovic
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, 1501 San Pablo Street, Los Angeles, California 90089, USA
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322
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Michalski D, Keck AL, Grosche J, Martens H, Härtig W. Immunosignals of Oligodendrocyte Markers and Myelin-Associated Proteins Are Critically Affected after Experimental Stroke in Wild-Type and Alzheimer Modeling Mice of Different Ages. Front Cell Neurosci 2018; 12:23. [PMID: 29467621 PMCID: PMC5807905 DOI: 10.3389/fncel.2018.00023] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Accepted: 01/15/2018] [Indexed: 12/31/2022] Open
Abstract
Because stroke therapies are still limited and patients are often concerned by long-term sequelae with significant impairment of daily living, elaborated neuroprotective strategies are needed. During the last decades, research substantially improved the knowledge on cellular pathologies responsible for stroke-related tissue damage. In this context, the neurovascular unit (NVU) concept has been established, summarizing the affections of neurons, associated astrocytes and the vasculature. Although oligodendrocytes were already identified to play a major role in other brain pathologies, their role during stroke evolution and long-lasting tissue damage is poorly understood. This study aims to explore oligodendrocyte structures, i.e., oligodendrocytes and their myelin-associated proteins, after experimental focal cerebral ischemia. For translational issues, different ages and genotypes including an Alzheimer-like background were considered to mimic potential co-morbidities. Three- and 12-month-old wild-type and triple-transgenic mice were subjected to unilateral middle cerebral artery occlusion. Immunofluorescence labeling was performed on forebrain tissues affected by 24 h of ischemia to visualize the oligodendrocyte-specific protein (OSP), the myelin basic protein (MBP), and the neuron-glia antigen 2 (NG2) with reference to the ischemic lesion. Subsequent analyses concomitantly detected the vasculature and the 2′, 3′-cyclic nucleotide-3′-phosphodiesterase (CNPase) to consider the NVU concept and to explore the functional relevance of histochemical data on applied oligodendrocyte markers. While the immunosignal of NG2 was found to be nearly absent 24 h after ischemia onset, enhanced immunoreactivities for OSP and especially MBP were observed in close regional association to the vasculature. Added quantitative analyses based on inter-hemispheric differences of MBP-immunoreactivity revealed a shell-like pattern with a significant increase directly in the ischemic core, followed by a gradual decline toward the striatum, the ischemic border zone and the lateral neocortex. This observation was consistent in subsequent analyses on the potential impact of age and genetic background. Furthermore, immunoreactivities for CNPase, MBP, and OSP were found to be simultaneously enhanced. In conclusion, this study provides evidence for a critical role of oligodendrocyte structures in the early phase after experimental stroke, strengthening their involvement in the ischemia-affected NVU. Consequently, oligodendrocytes and their myelin-associated proteins may qualify as potential targets for neuroprotective and regenerative approaches in stroke.
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Affiliation(s)
| | - Anna L Keck
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | | | | | - Wolfgang Härtig
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
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323
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Biological activities of (-)-epicatechin and (-)-epicatechin-containing foods: Focus on cardiovascular and neuropsychological health. Biotechnol Adv 2018; 36:666-681. [PMID: 29355598 DOI: 10.1016/j.biotechadv.2018.01.009] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 01/12/2018] [Accepted: 01/15/2018] [Indexed: 12/22/2022]
Abstract
Recent studies have suggested that certain (-)-epicatechin-containing foods have a blood pressure-lowering capacity. The mechanisms underlying (-)-epicatechin action may help prevent oxidative damage and endothelial dysfunction, which have both been associated with hypertension and certain brain disorders. Moreover, (-)-epicatechin has been shown to modify metabolic profile, blood's rheological properties, and to cross the blood-brain barrier. Thus, (-)-epicatechin causes multiple actions that may provide unique synergy beneficial for cardiovascular and neuropsychological health. This review summarises the current knowledge on the biological actions of (-)-epicatechin, related to cardiovascular and brain functions, which may play a remarkable role in human health and longevity.
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324
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Noh Y, Seo SW, Jeon S, Lee JM, Kim JS, Lee JH, Kim JH, Kim GH, Ye BS, Cho H, Kim HJ, Yoon CW, Choe YS, Lee KH, Weiner MW, Na DL. The Role of Cerebrovascular Disease in Amyloid Deposition. J Alzheimers Dis 2018; 54:1015-1026. [PMID: 27567803 DOI: 10.3233/jad-150832] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND Some patients clinically diagnosed with subcortical vascular cognitive impairment (SVCI) have co-morbidity with AD pathology. OBJECTIVE We investigated topographical differences in amyloid burden between SVCI and Alzheimer's disease type cognitive impairment (ADCI) using [11C] Pittsburgh compound B (PiB) positron emission tomography (PET). The purpose of this study was to investigate the role of cerebrovascular disease (CVD) in amyloid deposition. METHODS We recruited 44 patients with SVCI and 44 patients with ADCI (amnestic mild cognitive impairment or Alzheimer's disease) with absent or minimal white matter hyperintensities, all with PiB-positive PET scans [PiB+]. As controls, we included 13 participants with normal cognition and PiB-negative scans. We divided the SVCI and ADCI patients into three groups according to global PiB retention ratio of SVCI, and then compared the tertiles in terms of the distribution of PiB retention using statistical parametric mapping analyses. Lobar to global PiB retention ratio and asymmetry indices were also compared between SVCI and ADCI groupsResults: Compared to PiB+ ADCI patients, PiB+ SVCI patients exhibited: 1) increased left-right asymmetry, and increased anterior-posterior difference; and 2) increased PiB retention in the parietal cortex, the occipital cortex and the precuneus-posterior cingulate cortex. In contrast, ADCI patients showed increased PiB retention in the striatum. When stratified by level of PiB retention, each group showed different characteristics. CONCLUSION Our results showed that the distribution of amyloid deposition differed between patients with PiB+ SVCI and ADCI. These suggest that CVD contribute to and alter the known progression pattern in amyloid deposition in Alzheimer's disease.
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Affiliation(s)
- Young Noh
- Department of Neurology, Gachon University Gil Medical Center, Incheon, Republic of Korea.,Department of Health Sciences and Technology, GAIHST, Gachon University, Incheon, Republic of Korea
| | - Sang Won Seo
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.,Neuroscience Center, Samsung Medical Center, Seoul, Republic of Korea.,Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea.,Department of Clinical Research Design & Evaluation, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea
| | - Seun Jeon
- McGill Center for Integrative Neuroscience, Montreal Neurological Institute, McGill University, Montreal, Canada
| | - Jong Min Lee
- Department of Biomedical Engineering, Hanyang University, Seoul, Republic of Korea
| | - Jae Seung Kim
- Department of Nuclear Medicine, University of Ulsan College of Medicine, >Asan Medical Center, Seoul, Republic of Korea
| | - Jae-Hong Lee
- Department of Neurology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea
| | - Jung-Hyun Kim
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Geon Ha Kim
- Department of Neurology, Ewha Womans University Mokdong Hospital, Ewha Womans University School of Medicine, Seoul, Republic of Korea
| | - Byoung Seok Ye
- Department of Neurology, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Hanna Cho
- Department of Neurology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Hee Jin Kim
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.,Neuroscience Center, Samsung Medical Center, Seoul, Republic of Korea
| | - Cindy W Yoon
- Department of Neurology, Inha University Hospital, Inha University School of Medicine, Incheon, Republic of Korea
| | - Yearn Seong Choe
- Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Kyung-Han Lee
- Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Michael W Weiner
- University of California, San Francisco, San Francisco, CA, USA.,Department of Veterans Affairs Medical Center, Center for Imaging of Neurodegenerative Diseases, San Francisco, CA, USA
| | - Duk L Na
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.,Neuroscience Center, Samsung Medical Center, Seoul, Republic of Korea.,Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea.,Stem Cell & Regenerative Medicine Institute, Samsung Medical Center, Seoul, Republic of Korea
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325
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Shim JW, Madsen JR. VEGF Signaling in Neurological Disorders. Int J Mol Sci 2018; 19:ijms19010275. [PMID: 29342116 PMCID: PMC5796221 DOI: 10.3390/ijms19010275] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 01/06/2018] [Accepted: 01/10/2018] [Indexed: 12/19/2022] Open
Abstract
Vascular endothelial growth factor (VEGF) is a potent growth factor playing diverse roles in vasculogenesis and angiogenesis. In the brain, VEGF mediates angiogenesis, neural migration and neuroprotection. As a permeability factor, excessive VEGF disrupts intracellular barriers, increases leakage of the choroid plexus endothelia, evokes edema, and activates the inflammatory pathway. Recently, we discovered that a heparin binding epidermal growth factor like growth factor (HB-EGF)—a class of EGF receptor (EGFR) family ligands—contributes to the development of hydrocephalus with subarachnoid hemorrhage through activation of VEGF signaling. The objective of this review is to entail a recent update on causes of death due to neurological disorders involving cerebrovascular and age-related neurological conditions and to understand the mechanism by which angiogenesis-dependent pathological events can be treated with VEGF antagonisms. The Global Burden of Disease study indicates that cancer and cardiovascular disease including ischemic and hemorrhagic stroke are two leading causes of death worldwide. The literature suggests that VEGF signaling in ischemic brains highlights the importance of concentration, timing, and alternate route of modulating VEGF signaling pathway. Molecular targets distinguishing two distinct pathways of VEGF signaling may provide novel therapies for the treatment of neurological disorders and for maintaining lower mortality due to these conditions.
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Affiliation(s)
- Joon W Shim
- Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA.
| | - Joseph R Madsen
- Department of Neurosurgery, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA.
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326
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Maksimovich IV. Differences in Cerebral Angioarchitectonics in Alzheimer's Disease in Comparison with Other Neurodegenerative and Ischemic Lesions. ACTA ACUST UNITED AC 2018. [DOI: 10.4236/wjns.2018.84036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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327
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Nanotherapy for Alzheimer's disease and vascular dementia: Targeting senile endothelium. Adv Colloid Interface Sci 2018; 251:44-54. [PMID: 29274774 DOI: 10.1016/j.cis.2017.12.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Revised: 12/01/2017] [Accepted: 12/02/2017] [Indexed: 12/12/2022]
Abstract
Due to the complexity of Alzheimer's disease, multiple cellular types need to be targeted simultaneously in order for a given therapy to demonstrate any major effectiveness. Ultrasound-sensitive coated microbubbles (in a targeted lipid nanoemulsion) are available. Versatile small molecule drug(s) targeting multiple pathways of Alzheimer's disease pathogenesis are known. By incorporating such drug(s) into the targeted "lipid-coated microbubble" [LCM]/"nanoparticle-derived" [ND] (or LCM/ND) nanoemulsion type, one obtains a multitasking combination therapeutic for translational medicine. This multitasking therapeutic targets cell-surface scavenger receptors (mainly class B type I), or SR-BI, making possible for various Alzheimer's-related cell types to be simultaneously searched out for localized drug treatment in vivo. Besides targeting cell-surface SR-BI, the proposed LCM/ND-nanoemulsion combination therapeutic(s) include a characteristic lipid-coated microbubble [LCM] subpopulation (i.e., a stable LCM suspension); such film-stabilized microbubbles are well known to substantially reduce the acoustic power levels needed for accomplishing temporary noninvasive (transcranial) ultrasound treatment, or sonoporation, if additionally desired for the Alzheimer's patient.
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328
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Jorfi M, D'Avanzo C, Kim DY, Irimia D. Three-Dimensional Models of the Human Brain Development and Diseases. Adv Healthc Mater 2018; 7:10.1002/adhm.201700723. [PMID: 28845922 PMCID: PMC5762251 DOI: 10.1002/adhm.201700723] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Revised: 06/24/2017] [Indexed: 01/07/2023]
Abstract
Deciphering the human brain pathophysiology remains one of the greatest challenges of the 21st century. Neurological disorders represent a significant proportion of diseases burden; however, the complexity of the brain physiology makes it challenging to model its diseases. Simple in vitro models have been very useful for precise measurements in controled conditions. However, existing models are limited in their ability to replicate complex interactions between various cells in the brain. Studying human brain requires sophisticated models to reconstitute the tangled architecture and functions of brain cells. Recently, advances in the development of three-dimensional (3D) brain cell culture models have begun to recapitulate various aspects of the human brain physiology in vitro and replicate basic disease processes of Alzheimer's disease, amyotrophic lateral sclerosis, and microcephaly. In this review, we discuss the progress, advantages, limitations, and future directions of 3D cell culture systems for modeling the human brain development and diseases.
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Affiliation(s)
- Mehdi Jorfi
- Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, 02129, USA
| | - Carla D'Avanzo
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, 02129, USA
| | - Doo Yeon Kim
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, 02129, USA
| | - Daniel Irimia
- Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, 02129, USA
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329
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Hall CN, Howarth C, Kurth-Nelson Z, Mishra A. Interpreting BOLD: towards a dialogue between cognitive and cellular neuroscience. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0348. [PMID: 27574302 DOI: 10.1098/rstb.2015.0348] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/11/2016] [Indexed: 12/11/2022] Open
Abstract
Cognitive neuroscience depends on the use of blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) to probe brain function. Although commonly used as a surrogate measure of neuronal activity, BOLD signals actually reflect changes in brain blood oxygenation. Understanding the mechanisms linking neuronal activity to vascular perfusion is, therefore, critical in interpreting BOLD. Advances in cellular neuroscience demonstrating differences in this neurovascular relationship in different brain regions, conditions or pathologies are often not accounted for when interpreting BOLD. Meanwhile, within cognitive neuroscience, the increasing use of high magnetic field strengths and the development of model-based tasks and analyses have broadened the capability of BOLD signals to inform us about the underlying neuronal activity, but these methods are less well understood by cellular neuroscientists. In 2016, a Royal Society Theo Murphy Meeting brought scientists from the two communities together to discuss these issues. Here, we consolidate the main conclusions arising from that meeting. We discuss areas of consensus about what BOLD fMRI can tell us about underlying neuronal activity, and how advanced modelling techniques have improved our ability to use and interpret BOLD. We also highlight areas of controversy in understanding BOLD and suggest research directions required to resolve these issues.This article is part of the themed issue 'Interpreting BOLD: a dialogue between cognitive and cellular neuroscience'.
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Affiliation(s)
| | - Clare Howarth
- Department of Psychology, University of Sheffield, Sheffield, UK
| | - Zebulun Kurth-Nelson
- Max Planck UCL Centre for Computational Psychiatry and Ageing Research, University College London, London, UK
| | - Anusha Mishra
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
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330
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Alzheimer’s Disease, Brain Injury, and C.N.S. Nanotherapy in Humans: Sonoporation Augmenting Drug Targeting. Med Sci (Basel) 2017. [PMCID: PMC5753658 DOI: 10.3390/medsci5040029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Owing to the complexity of neurodegenerative diseases, multiple cellular types need to be targeted simultaneously in order for a given therapy to demonstrate any major effectiveness. Ultrasound-sensitive coated microbubbles (in a targeted nanoemulsion) are available. Versatile small-molecule drug(s) targeting multiple pathways of Alzheimer’s disease pathogenesis are known. By incorporating such drug(s) into the targeted lipid-coated microbubble/nanoparticle-derived (LCM/ND) lipid nanoemulsion type, one obtains a multitasking combination therapeutic for translational medicine. This multitasking therapeutic targets cell-surface scavenger receptors (mainly scavenger receptor class B type I (SR-BI)), making it possible for various Alzheimer’s-related cell types to be simultaneously sought for localized drug treatment in vivo. Besides targeting cell-surface SR-BI, the proposed LCM/ND-nanoemulsion combination therapeutic(s) include a characteristic lipid-coated microbubble (LCM) subpopulation (i.e., a stable LCM suspension); such LCM substantially reduce the acoustic power levels needed for accomplishing temporary noninvasive (transcranial) ultrasound treatment, or sonoporation, if additionally desired for the Alzheimer’s patient.
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331
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Montagne A, Zhao Z, Zlokovic BV. Alzheimer's disease: A matter of blood-brain barrier dysfunction? J Exp Med 2017; 214:3151-3169. [PMID: 29061693 PMCID: PMC5679168 DOI: 10.1084/jem.20171406] [Citation(s) in RCA: 433] [Impact Index Per Article: 61.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Revised: 09/22/2017] [Accepted: 09/26/2017] [Indexed: 12/22/2022] Open
Abstract
Montagne et al. examine the role of blood–brain barrier (BBB) dysfunction in Alzheimer’s neurodegeneration and how targeting the BBB can influence the course of neurological disorder in transgenic models with human APP, PSEN1 and TAU mutations, APOE4 (major genetic risk), and pericyte degeneration causing loss of BBB integrity. The blood–brain barrier (BBB) keeps neurotoxic plasma-derived components, cells, and pathogens out of the brain. An early BBB breakdown and/or dysfunction have been shown in Alzheimer’s disease (AD) before dementia, neurodegeneration and/or brain atrophy occur. However, the role of BBB breakdown in neurodegenerative disorders is still not fully understood. Here, we examine BBB breakdown in animal models frequently used to study the pathophysiology of AD, including transgenic mice expressing human amyloid-β precursor protein, presenilin 1, and tau mutations, and apolipoprotein E, the strongest genetic risk factor for AD. We discuss the role of BBB breakdown and dysfunction in neurodegenerative process, pitfalls in BBB measurements, and how targeting the BBB can influence the course of neurological disorder. Finally, we comment on future approaches and models to better define, at the cellular and molecular level, the underlying mechanisms between BBB breakdown and neurodegeneration as a basis for developing new therapies for BBB repair to control neurodegeneration.
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Affiliation(s)
- Axel Montagne
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, Los Angeles, CA.,Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, Los Angeles, CA
| | - Zhen Zhao
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, Los Angeles, CA.,Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, Los Angeles, CA
| | - Berislav V Zlokovic
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, Los Angeles, CA.,Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, Los Angeles, CA
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332
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Al-Bachari S, Vidyasagar R, Emsley HC, Parkes LM. Structural and physiological neurovascular changes in idiopathic Parkinson's disease and its clinical phenotypes. J Cereb Blood Flow Metab 2017; 37:3409-3421. [PMID: 28112022 PMCID: PMC5624390 DOI: 10.1177/0271678x16688919] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Neurovascular changes are likely to interact importantly with the neurodegenerative process in idiopathic Parkinson's disease (IPD). Markers of neurovascular status (NVS) include white matter lesion (WML) burden and arterial spin labelling (ASL) measurements of cerebral blood flow (CBF) and arterial arrival time (AAT). We investigated NVS in IPD, including an analysis of IPD clinical phenotypes, by comparison with two control groups, one with a history of clinical cerebrovascular disease (CVD) (control positive, CP) and one without CVD (control negative, CN). Fifty-one patients with IPD (mean age 69.0 ± 7.7 years) (21 tremor dominant (TD), 24 postural instability and gait disorder (PIGD) and six intermediates), 18 CP (mean age 70.1 ± 8.0 years) and 34 CN subjects (mean age 67.4 ± 7.6 years) completed a 3T MRI scan protocol including T2-weighted fluid-attenuated inversion recovery (FLAIR) and ASL. IPD patients showed diffuse regions of significantly prolonged AAT, small regions of lower CBF and greater WML burden by comparison with CN subjects. TD patients showed lower WML volume by comparison with PIGD patients. These imaging data thus show altered NVS in IPD, with some evidence for IPD phenotype-specific differences.
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Affiliation(s)
- Sarah Al-Bachari
- 1 Department of Neurology, Salford Royal NHS Foundation Trust, Salford, UK.,2 Division of Informatics, Imaging and Data Sciences, School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.,3 Faculty of Health and Medicine, Lancaster University, Lancaster, UK
| | - Rishma Vidyasagar
- 2 Division of Informatics, Imaging and Data Sciences, School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.,4 Anatomy and Neuroscience Department, University of Melbourne, Melbourne, Australia.,5 Florey Institute of Neuroscience and Mental Health, Heidelberg, Melbourne, Australia
| | - Hedley Ca Emsley
- 6 Department of Neurology, Royal Preston Hospital, Preston, UK.,7 Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Laura M Parkes
- 2 Division of Informatics, Imaging and Data Sciences, School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.,8 Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
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333
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Charidimou A, Boulouis G, Gurol ME, Ayata C, Bacskai BJ, Frosch MP, Viswanathan A, Greenberg SM. Emerging concepts in sporadic cerebral amyloid angiopathy. Brain 2017; 140:1829-1850. [PMID: 28334869 DOI: 10.1093/brain/awx047] [Citation(s) in RCA: 296] [Impact Index Per Article: 42.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 01/17/2017] [Indexed: 12/27/2022] Open
Abstract
Sporadic cerebral amyloid angiopathy is a common, well-defined small vessel disease and a largely untreatable cause of intracerebral haemorrhage and contributor to age-related cognitive decline. The term 'cerebral amyloid angiopathy' now encompasses not only a specific cerebrovascular pathological finding, but also different clinical syndromes (both acute and progressive), brain parenchymal lesions seen on neuroimaging and a set of diagnostic criteria-the Boston criteria, which have resulted in increasingly detected disease during life. Over the past few years, it has become clear that, at the pathophysiological level, cerebral amyloid angiopathy appears to be in part a protein elimination failure angiopathy and that this dysfunction is a feed-forward process, which potentially leads to worsening vascular amyloid-β accumulation, activation of vascular injury pathways and impaired vascular physiology. From a clinical standpoint, cerebral amyloid angiopathy is characterized by individual focal lesions (microbleeds, cortical superficial siderosis, microinfarcts) and large-scale alterations (white matter hyperintensities, structural connectivity, cortical thickness), both cortical and subcortical. This review provides an interdisciplinary critical outlook on various emerging and changing concepts in the field, illustrating mechanisms associated with amyloid cerebrovascular pathology and neurological dysfunction.
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Affiliation(s)
- Andreas Charidimou
- Hemorrhagic Stroke Research Program, Department of Neurology, Massachusetts General Hospital Stroke Research Center, Harvard Medical School, Boston, MA, USA
| | - Gregoire Boulouis
- Hemorrhagic Stroke Research Program, Department of Neurology, Massachusetts General Hospital Stroke Research Center, Harvard Medical School, Boston, MA, USA
| | - M Edip Gurol
- Hemorrhagic Stroke Research Program, Department of Neurology, Massachusetts General Hospital Stroke Research Center, Harvard Medical School, Boston, MA, USA
| | - Cenk Ayata
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA.,Stroke Service and Neuroscience Intensive Care Unit, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Brian J Bacskai
- Alzheimer Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 114, 16th St., Charlestown, MA 02129, USA
| | - Matthew P Frosch
- Alzheimer Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 114, 16th St., Charlestown, MA 02129, USA.,C.S. Kubik Laboratory for Neuropathology, Department of Pathology, Massachusetts General Hospital and Harvard Medical School, 114, 16th St., Charlestown, MA 02129, USA
| | - Anand Viswanathan
- Hemorrhagic Stroke Research Program, Department of Neurology, Massachusetts General Hospital Stroke Research Center, Harvard Medical School, Boston, MA, USA
| | - Steven M Greenberg
- Hemorrhagic Stroke Research Program, Department of Neurology, Massachusetts General Hospital Stroke Research Center, Harvard Medical School, Boston, MA, USA.,Alzheimer Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 114, 16th St., Charlestown, MA 02129, USA
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334
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Csiszar A, Tarantini S, Fülöp GA, Kiss T, Valcarcel-Ares MN, Galvan V, Ungvari Z, Yabluchanskiy A. Hypertension impairs neurovascular coupling and promotes microvascular injury: role in exacerbation of Alzheimer's disease. GeroScience 2017; 39:359-372. [PMID: 28853030 PMCID: PMC5636770 DOI: 10.1007/s11357-017-9991-9] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 07/26/2017] [Indexed: 12/13/2022] Open
Abstract
Hypertension in the elderly substantially increases both the risk of vascular cognitive impairment (VCI) and Alzheimer's disease (AD); however, the underlying mechanisms are not completely understood. This review discusses the effects of hypertension on structural and functional integrity of cerebral microcirculation, including hypertension-induced alterations in neurovascular coupling responses, cellular and molecular mechanisms involved in microvascular damage (capillary rarefaction, blood-brain barrier disruption), and the genesis of cerebral microhemorrhages and their potential role in exacerbation of cognitive decline associated with AD. Understanding and targeting the hypertension-induced cerebromicrovascular alterations that are involved in the onset and progression of AD and contribute to cognitive impairment are expected to have a major role in preserving brain health in high-risk older individuals.
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Affiliation(s)
- Anna Csiszar
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Translational Geroscience Laboratory, Donald W. Reynolds Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Stefano Tarantini
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Translational Geroscience Laboratory, Donald W. Reynolds Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Gábor A Fülöp
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Translational Geroscience Laboratory, Donald W. Reynolds Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Division of Clinical Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Tamas Kiss
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Translational Geroscience Laboratory, Donald W. Reynolds Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - M Noa Valcarcel-Ares
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Translational Geroscience Laboratory, Donald W. Reynolds Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Veronica Galvan
- Department of Cellular and Integrative Physiology, Barshop Institute for Longevity and Aging Studies University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Zoltan Ungvari
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Translational Geroscience Laboratory, Donald W. Reynolds Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Andriy Yabluchanskiy
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
- Translational Geroscience Laboratory, Donald W. Reynolds Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
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335
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Michalski D, Hofmann S, Pitsch R, Grosche J, Härtig W. Neurovascular Specifications in the Alzheimer-Like Brain of Mice Affected by Focal Cerebral Ischemia: Implications for Future Therapies. J Alzheimers Dis 2017; 59:655-674. [DOI: 10.3233/jad-170185] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
| | - Sarah Hofmann
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Roman Pitsch
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | | | - Wolfgang Härtig
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
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336
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Guerra M, Blázquez JL, Rodríguez EM. Blood-brain barrier and foetal-onset hydrocephalus, with a view on potential novel treatments beyond managing CSF flow. Fluids Barriers CNS 2017; 14:19. [PMID: 28701191 PMCID: PMC5508761 DOI: 10.1186/s12987-017-0067-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 06/24/2017] [Indexed: 12/12/2022] Open
Abstract
Despite decades of research, no compelling non-surgical therapies have been developed for foetal hydrocephalus. So far, most efforts have pointed to repairing disturbances in the cerebrospinal fluid (CSF) flow and to avoid further brain damage. There are no reports trying to prevent or diminish abnormalities in brain development which are inseparably associated with hydrocephalus. A key problem in the treatment of hydrocephalus is the blood–brain barrier that restricts the access to the brain for therapeutic compounds or systemically grafted cells. Recent investigations have started to open an avenue for the development of a cell therapy for foetal-onset hydrocephalus. Potential cells to be used for brain grafting include: (1) pluripotential neural stem cells; (2) mesenchymal stem cells; (3) genetically-engineered stem cells; (4) choroid plexus cells and (5) subcommissural organ cells. Expected outcomes are a proper microenvironment for the embryonic neurogenic niche and, consequent normal brain development.
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Affiliation(s)
- M Guerra
- Instituto de Anatomía, Histología y Patología, Facultad de Medicina, Universidad Austral de Chile, Valdivia, Chile.
| | - J L Blázquez
- Departamento de Anatomía e Histología Humana, Facultad de Medicina, Universidad de Salamanca, Salamanca, Spain
| | - E M Rodríguez
- Instituto de Anatomía, Histología y Patología, Facultad de Medicina, Universidad Austral de Chile, Valdivia, Chile
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337
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Skillbäck T, Delsing L, Synnergren J, Mattsson N, Janelidze S, Nägga K, Kilander L, Hicks R, Wimo A, Winblad B, Hansson O, Blennow K, Eriksdotter M, Zetterberg H. CSF/serum albumin ratio in dementias: a cross-sectional study on 1861 patients. Neurobiol Aging 2017; 59:1-9. [PMID: 28779628 DOI: 10.1016/j.neurobiolaging.2017.06.028] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 06/29/2017] [Accepted: 06/30/2017] [Indexed: 11/26/2022]
Abstract
A connection between dementias and blood-brain barrier (BBB) dysfunction has been suggested, but previous studies have yielded conflicting results. We examined cerebrospinal fluid (CSF)/serum albumin ratio in a large cohort of patients diagnosed with Alzheimer's disease (AD, early onset [EAD, n = 130], late onset AD [LAD, n = 666]), vascular dementia (VaD, n = 255), mixed AD and VaD (MIX, n = 362), Lewy body dementia (DLB, n = 50), frontotemporal dementia (FTD, n = 56), Parkinson's disease dementia (PDD, n = 23), other dementias (other, n = 48), and dementia not otherwise specified (NOS, n = 271). We compared CSF/serum albumin ratio to 2 healthy control groups (n = 292, n = 20), between dementia diagnoses, and tested biomarker associations. Patients in DLB, LAD, VaD, MIX, other, and NOS groups had higher CSF/serum albumin ratio than controls. CSF/serum albumin ratio correlated with CSF neurofilament light in LAD, MIX, VaD, and other groups but not with AD biomarkers. Our data show that BBB leakage is common in dementias. The lack of association between CSF/serum albumin ratio and AD biomarkers suggests that BBB dysfunction is not inherent to AD but might represent concomitant cerebrovascular pathology.
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Affiliation(s)
- Tobias Skillbäck
- Department of Neurochemistry, Institute of Neuroscience and Physiology, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
| | - Louise Delsing
- Department of Neurochemistry, Institute of Neuroscience and Physiology, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden; Systems Biology Research Center, School of Bioscience, University of Skövde, Skövde, Sweden.
| | - Jane Synnergren
- Systems Biology Research Center, School of Bioscience, University of Skövde, Skövde, Sweden
| | - Niklas Mattsson
- Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden; Department of Neurology, Skåne University Hospital, Lund, Sweden
| | - Shorena Janelidze
- Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden
| | - Katarina Nägga
- Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden
| | - Lena Kilander
- Department of Public Health and Caring Sciences/Geriatrics, Uppsala University, Uppsala, Sweden
| | - Ryan Hicks
- Discovery Sciences, IMED Biotech Unit, AstraZeneca, Mölndal, Sweden
| | - Anders Wimo
- Centre for Research and Development, Uppsala University/County Council of Gävleborg, Gävle, Sweden; Division for Neurogeriatrics, Department of Neurobiology, Care Sciences, and Society (NVS), Center for Alzheimer Research, Karolinska Institutet, Huddinge, Sweden
| | - Bengt Winblad
- Division for Neurogeriatrics, Department of Neurobiology, Care Sciences, and Society (NVS), Center for Alzheimer Research, Karolinska Institutet, Huddinge, Sweden; Department Geriatric Medicine, Karolinska University Hospital, Huddinge, Sweden
| | - Oskar Hansson
- Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden; Department of Neurology, Skåne University Hospital, Lund, Sweden
| | - Kaj Blennow
- Department of Neurochemistry, Institute of Neuroscience and Physiology, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
| | - Maria Eriksdotter
- Department Geriatric Medicine, Karolinska University Hospital, Huddinge, Sweden; Division of Clinical Geriatrics, Department of Neurobiology, Care Sciences, and Society (NVS), Center for Alzheimer Research, Karolinska Institutet, Huddinge, Sweden
| | - Henrik Zetterberg
- Department of Neurochemistry, Institute of Neuroscience and Physiology, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden; Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK; UK Dementia Research Institute at UCL, London, UK
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Shirzadi Z, Stefanovic B, Chappell MA, Ramirez J, Schwindt G, Masellis M, Black SE, MacIntosh BJ. Enhancement of automated blood flow estimates (ENABLE) from arterial spin-labeled MRI. J Magn Reson Imaging 2017; 47:647-655. [DOI: 10.1002/jmri.25807] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 06/20/2017] [Indexed: 11/06/2022] Open
Affiliation(s)
- Zahra Shirzadi
- Department of Medical Biophysics; University of Toronto; Toronto ON Canada
- Heart and Stroke Foundation, Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute; University of Toronto; Toronto ON Canada
- Hurvitz Brain Sciences, Sunnybrook Research Institute; University of Toronto; Toronto ON Canada
| | - Bojana Stefanovic
- Department of Medical Biophysics; University of Toronto; Toronto ON Canada
- Heart and Stroke Foundation, Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute; University of Toronto; Toronto ON Canada
- Hurvitz Brain Sciences, Sunnybrook Research Institute; University of Toronto; Toronto ON Canada
| | - Michael A. Chappell
- Institute of Biomedical Engineering, Department of Engineering Science; University of Oxford; Oxford UK
- Oxford Centre for Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences; University of Oxford; Oxford UK
| | - Joel Ramirez
- Heart and Stroke Foundation, Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute; University of Toronto; Toronto ON Canada
- Hurvitz Brain Sciences, Sunnybrook Research Institute; University of Toronto; Toronto ON Canada
| | - Graeme Schwindt
- Hurvitz Brain Sciences, Sunnybrook Research Institute; University of Toronto; Toronto ON Canada
- Department of Family and Community Medicine; University of Toronto; Toronto ON Canada
| | - Mario Masellis
- Heart and Stroke Foundation, Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute; University of Toronto; Toronto ON Canada
- Hurvitz Brain Sciences, Sunnybrook Research Institute; University of Toronto; Toronto ON Canada
- Department of Medicine (Neurology), Sunnybrook Health Sciences Centre; University of Toronto; Toronto ON Canada
| | - Sandra E. Black
- Heart and Stroke Foundation, Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute; University of Toronto; Toronto ON Canada
- Hurvitz Brain Sciences, Sunnybrook Research Institute; University of Toronto; Toronto ON Canada
- Department of Medicine (Neurology), Sunnybrook Health Sciences Centre; University of Toronto; Toronto ON Canada
| | - Bradley J. MacIntosh
- Department of Medical Biophysics; University of Toronto; Toronto ON Canada
- Heart and Stroke Foundation, Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute; University of Toronto; Toronto ON Canada
- Hurvitz Brain Sciences, Sunnybrook Research Institute; University of Toronto; Toronto ON Canada
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Ramirez AI, de Hoz R, Salobrar-Garcia E, Salazar JJ, Rojas B, Ajoy D, López-Cuenca I, Rojas P, Triviño A, Ramírez JM. The Role of Microglia in Retinal Neurodegeneration: Alzheimer's Disease, Parkinson, and Glaucoma. Front Aging Neurosci 2017; 9:214. [PMID: 28729832 PMCID: PMC5498525 DOI: 10.3389/fnagi.2017.00214] [Citation(s) in RCA: 296] [Impact Index Per Article: 42.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 06/16/2017] [Indexed: 12/12/2022] Open
Abstract
Microglia, the immunocompetent cells of the central nervous system (CNS), act as neuropathology sensors and are neuroprotective under physiological conditions. Microglia react to injury and degeneration with immune-phenotypic and morphological changes, proliferation, migration, and inflammatory cytokine production. An uncontrolled microglial response secondary to sustained CNS damage can put neuronal survival at risk due to excessive inflammation. A neuroinflammatory response is considered among the etiological factors of the major aged-related neurodegenerative diseases of the CNS, and microglial cells are key players in these neurodegenerative lesions. The retina is an extension of the brain and therefore the inflammatory response in the brain can occur in the retina. The brain and retina are affected in several neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), and glaucoma. AD is an age-related neurodegeneration of the CNS characterized by neuronal and synaptic loss in the cerebral cortex, resulting in cognitive deficit and dementia. The extracellular deposits of beta-amyloid (Aβ) and intraneuronal accumulations of hyperphosphorylated tau protein (pTau) are the hallmarks of this disease. These deposits are also found in the retina and optic nerve. PD is a neurodegenerative locomotor disorder with the progressive loss of dopaminergic neurons in the substantia nigra. This is accompanied by Lewy body inclusion composed of α-synuclein (α-syn) aggregates. PD also involves retinal dopaminergic cell degeneration. Glaucoma is a multifactorial neurodegenerative disease of the optic nerve, characterized by retinal ganglion cell loss. In this pathology, deposition of Aβ, synuclein, and pTau has also been detected in retina. These neurodegenerative diseases share a common pathogenic mechanism, the neuroinflammation, in which microglia play an important role. Microglial activation has been reported in AD, PD, and glaucoma in relation to protein aggregates and degenerated neurons. The activated microglia can release pro-inflammatory cytokines which can aggravate and propagate neuroinflammation, thereby degenerating neurons and impairing brain as well as retinal function. The aim of the present review is to describe the contribution in retina to microglial-mediated neuroinflammation in AD, PD, and glaucomatous neurodegeneration.
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Affiliation(s)
- Ana I. Ramirez
- Instituto de Investigaciones Oftalmológicas Ramón Castroviejo. Universidad Complutense de MadridMadrid, Spain
- Departamento de Oftalmología y ORL, Facultad de Óptica y Optometría, Universidad Complutense de Madrid (UCM)Madrid, Spain
| | - Rosa de Hoz
- Instituto de Investigaciones Oftalmológicas Ramón Castroviejo. Universidad Complutense de MadridMadrid, Spain
- Departamento de Oftalmología y ORL, Facultad de Óptica y Optometría, Universidad Complutense de Madrid (UCM)Madrid, Spain
| | - Elena Salobrar-Garcia
- Instituto de Investigaciones Oftalmológicas Ramón Castroviejo. Universidad Complutense de MadridMadrid, Spain
- Departamento de Oftalmología y ORL, Facultad de Medicina, Universidad Complutense de Madrid (UCM)Madrid, Spain
| | - Juan J. Salazar
- Instituto de Investigaciones Oftalmológicas Ramón Castroviejo. Universidad Complutense de MadridMadrid, Spain
- Departamento de Oftalmología y ORL, Facultad de Óptica y Optometría, Universidad Complutense de Madrid (UCM)Madrid, Spain
| | - Blanca Rojas
- Instituto de Investigaciones Oftalmológicas Ramón Castroviejo. Universidad Complutense de MadridMadrid, Spain
- Departamento de Oftalmología y ORL, Facultad de Medicina, Universidad Complutense de Madrid (UCM)Madrid, Spain
| | - Daniel Ajoy
- Instituto de Investigaciones Oftalmológicas Ramón Castroviejo. Universidad Complutense de MadridMadrid, Spain
| | - Inés López-Cuenca
- Instituto de Investigaciones Oftalmológicas Ramón Castroviejo. Universidad Complutense de MadridMadrid, Spain
| | - Pilar Rojas
- Instituto de Investigaciones Oftalmológicas Ramón Castroviejo. Universidad Complutense de MadridMadrid, Spain
- Servicio de Oftalmología, Hospital Gregorio MarañónMadrid, Spain
| | - Alberto Triviño
- Instituto de Investigaciones Oftalmológicas Ramón Castroviejo. Universidad Complutense de MadridMadrid, Spain
- Departamento de Oftalmología y ORL, Facultad de Medicina, Universidad Complutense de Madrid (UCM)Madrid, Spain
| | - José M. Ramírez
- Instituto de Investigaciones Oftalmológicas Ramón Castroviejo. Universidad Complutense de MadridMadrid, Spain
- Departamento de Oftalmología y ORL, Facultad de Medicina, Universidad Complutense de Madrid (UCM)Madrid, Spain
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340
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Kisler K, Nelson AR, Montagne A, Zlokovic BV. Cerebral blood flow regulation and neurovascular dysfunction in Alzheimer disease. Nat Rev Neurosci 2017; 18:419-434. [PMID: 28515434 PMCID: PMC5759779 DOI: 10.1038/nrn.2017.48] [Citation(s) in RCA: 738] [Impact Index Per Article: 105.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Cerebral blood flow (CBF) regulation is essential for normal brain function. The mammalian brain has evolved a unique mechanism for CBF control known as neurovascular coupling. This mechanism ensures a rapid increase in the rate of CBF and oxygen delivery to activated brain structures. The neurovascular unit is composed of astrocytes, mural vascular smooth muscle cells and pericytes, and endothelia, and regulates neurovascular coupling. This Review article examines the cellular and molecular mechanisms within the neurovascular unit that contribute to CBF control, and neurovascular dysfunction in neurodegenerative disorders such as Alzheimer disease.
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Affiliation(s)
- Kassandra Kisler
- Zilkha Neurogenetic Institute, 1501 San Pablo Street, Los Angeles, California 90089, USA
| | - Amy R Nelson
- Zilkha Neurogenetic Institute, 1501 San Pablo Street, Los Angeles, California 90089, USA
| | - Axel Montagne
- Zilkha Neurogenetic Institute, 1501 San Pablo Street, Los Angeles, California 90089, USA
| | - Berislav V Zlokovic
- Zilkha Neurogenetic Institute, 1501 San Pablo Street, Los Angeles, California 90089, USA
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341
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Moretti R, Caruso P, Dal Ben M, Conti C, Gazzin S, Tiribelli C. Vitamin D, Homocysteine, and Folate in Subcortical Vascular Dementia and Alzheimer Dementia. Front Aging Neurosci 2017; 9:169. [PMID: 28611659 PMCID: PMC5447683 DOI: 10.3389/fnagi.2017.00169] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 05/15/2017] [Indexed: 01/09/2023] Open
Abstract
Dementia is a worldwide health problem which affects millions of patients; Alzheimer's disease (AD) and subcortical vascular dementia (sVAD) are the two most frequent forms of its presentation. As no definite therapeutic options have been discovered, different risk factors for cognitive impairment have been searched for potential therapies. This report focuses on the possible evidence that vitamin D deficiency and hyper-homocysteinemia can be considered as two important factors for the development or the progression of neurodegenerative or vascular pathologies. To this end, we assessed: the difference in vascular risk factors and vitamin D-OH25 levels among groups of sVAD, AD, and healthy age-matched controls; the association of folate, B12, homocysteine, and vitamin D with sVAD/AD and whether a deficiency of vitamin D and an increment in homocysteine levels may be related to neurodegenerative or vessel damages. The commonly-considered vascular risk factors were collected in 543 patients and compared with those obtained from a healthy old volunteer population. ANOVA group comparison showed that vitamin D deficiency was present in demented cases, as well as low levels of folate and high levels of homocysteine, more pronounced in sVAD cases. The statistical models we employed, with regression models built, and adjustments for biochemical, demographic and neuropsychiatric scores, confirmed the association between the three measures (folate decrease, hyperhomocysteinemia and vitamin D decrease) and dementia, more pronounced in sVAD than in AD.
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Affiliation(s)
- Rita Moretti
- Neurology Clinic, Department of Medical, Surgical and Health Sciences, University of TriesteTrieste, Italy
| | - Paola Caruso
- Neurology Clinic, Department of Medical, Surgical and Health Sciences, University of TriesteTrieste, Italy
| | - Matteo Dal Ben
- Neurology Clinic, Department of Medical, Surgical and Health Sciences, University of TriesteTrieste, Italy.,Italian Liver Foundation, Centro Studi FegatoTrieste, Italy
| | - Corrado Conti
- Neurology Clinic, Department of Medical, Surgical and Health Sciences, University of TriesteTrieste, Italy
| | - Silvia Gazzin
- Italian Liver Foundation, Centro Studi FegatoTrieste, Italy
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342
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Bordet R, Ihl R, Korczyn AD, Lanza G, Jansa J, Hoerr R, Guekht A. Towards the concept of disease-modifier in post-stroke or vascular cognitive impairment: a consensus report. BMC Med 2017; 15:107. [PMID: 28539119 PMCID: PMC5444106 DOI: 10.1186/s12916-017-0869-6] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 05/06/2017] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Vascular cognitive impairment (VCI) is a complex spectrum encompassing post-stroke cognitive impairment (PSCI) and small vessel disease-related cognitive impairment. Despite the growing health, social, and economic burden of VCI, to date, no specific treatment is available, prompting the introduction of the concept of a disease modifier. CONSENSUS AND SUGGESTIONS Within this clinical spectrum, VCI and PSCI remain advancing conditions as neurodegenerative diseases with progression of both vascular and degenerative lesions accounting for cognitive decline. Disease-modifying strategies should integrate both pharmacological and non-pharmacological multimodal approaches, with pleiotropic effects targeting (1) endothelial and brain-blood barrier dysfunction; (2) neuronal death and axonal loss; (3) cerebral plasticity and compensatory mechanisms; and (4) degenerative-related protein misfolding. Moreover, pharmacological and non-pharmacological treatment in PSCI or VCI requires valid study designs clearly stating the definition of basic methodological issues, such as the instruments that should be used to measure eventual changes, the biomarker-based stratification of participants to be investigated, and statistical tests, as well as the inclusion and exclusion criteria that should be applied. CONCLUSION A consensus emerged to propose the development of a disease-modifying strategy in VCI and PSCI based on pleiotropic pharmacological and non-pharmacological approaches.
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Affiliation(s)
- Régis Bordet
- University of Lille, Inserm, CHU, U1171 'Degenerative and vascular cognitive disorders', Lille, France.
- Département de Pharmacologie Médicale, Faculté de Médecine, 1 place Verdun, 59045, Lille Cedex, France.
| | - Ralf Ihl
- University of Duesseldorf, Alexian Research Center, Krefeld, Germany
| | - Amos D Korczyn
- Department of Neurology, Tel Aviv University, Ramat Aviv, Israel
| | - Giuseppe Lanza
- Department of Neurology IC, Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Troina, Italy
| | - Jelka Jansa
- University Medical Centre Ljubljana, Neurologic Hospital, Neurorehabilitation Unit, Ljubljana, Slovenia
| | - Robert Hoerr
- Dr. Willmar Schwabe GmbH & Co. KG, Karlsruhe, Germany
| | - Alla Guekht
- Department of Neurology, Neurosurgery and Genetics, Russian National Research Medical University, Moscow Research and Clinical Center for Neuropsychiatry, Moscow, Russia
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343
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Lucero J, Suwannasual U, Herbert LM, McDonald JD, Lund AK. The role of the lectin-like oxLDL receptor (LOX-1) in traffic-generated air pollution exposure-mediated alteration of the brain microvasculature in Apolipoprotein (Apo) E knockout mice. Inhal Toxicol 2017; 29:266-281. [PMID: 28816559 PMCID: PMC6732220 DOI: 10.1080/08958378.2017.1357774] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Accepted: 07/17/2017] [Indexed: 12/30/2022]
Abstract
Recent studies have shown a strong correlation between air pollution-exposure and detrimental outcomes in the central nervous system, including alterations in blood brain barrier (BBB) integrity, neuroinflammation, and neurodegeneration. However, the mechanisms mediating these pathologies have not yet been fully elucidated. We have previously reported that exposure to traffic-generated air pollution results in increased circulating oxidized low-density lipoprotein (oxLDL), associated with alterations in BBB integrity, in atherosclerotic Apolipoprotein E null (ApoE-/-) mice. Thus, we investigated the role of the lectin-like oxLDL receptor (LOX)-1 in mediating these deleterious effects in ApoE-/- mice exposed to a mixture of gasoline and diesel engine exhaust (MVE: 100 PM µg/m3) for 6 h/d, 7d/week, for 30 d by inhalation. Concurrent with exposures, a subset of mice were treated with neutralizing antibodies to LOX-1 (LOX-1 Ab) i.p., or IgG (control) i.p., every other day during exposures. Resulting brain microvascular integrity, tight junction (TJ) protein expression, matrix metalloproteinase (MMP)-9/-2 activity, ROS, and markers of cellular adhesion and monocyte/macrophage sequestration were assessed. MVE-exposure resulted in decreased BBB integrity and alterations in microvascular TJ protein expression, associated with increased LOX-1 expression, MMP-9/-2 activities, and lipid peroxidation, each of which was attenuated with LOX-1 Ab treatment. Furthermore, MVE-exposure induced cerebral microvascular ROS and adhesion molecules, expression of which was not normalized through LOX-1 Ab-treatment. Such findings suggest that alterations in brain microvascular structure and integrity observed with MVE-exposure may be mediated, at least in part, via LOX-1 signaling.
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Affiliation(s)
- JoAnn Lucero
- Advanced Environmental Research Institute, Department of Biological Sciences, University of North Texas, Denton, TX, USA
| | - Usa Suwannasual
- Advanced Environmental Research Institute, Department of Biological Sciences, University of North Texas, Denton, TX, USA
| | - Lindsay M. Herbert
- Cell Biology and Physiology, University of New Mexico, Albuquerque, NM, USA
| | - Jacob D. McDonald
- Lovelace Biomedical and Environmental Research Institute, Albuquerque, NM, USA
| | - Amie K. Lund
- Advanced Environmental Research Institute, Department of Biological Sciences, University of North Texas, Denton, TX, USA
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344
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Choi JY, Yoon SS, Kim SE, Ahn Jo S. KDM4B histone demethylase and G9a regulate expression of vascular adhesion proteins in cerebral microvessels. Sci Rep 2017; 7:45005. [PMID: 28327608 PMCID: PMC5361151 DOI: 10.1038/srep45005] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 02/17/2017] [Indexed: 12/16/2022] Open
Abstract
Intercellular adhesion molecule 1 (ICAM1) mediates the adhesion and transmigration of leukocytes across the endothelium, promoting inflammation. We investigated the epigenetic mechanism regulating ICAM1 expression. The pro-inflammatory cytokine TNF-α dramatically increased ICAM1 mRNA and protein levels in human brain microvascular endothelial cells and mouse brain microvessels. Chromatin immunoprecipitation revealed that TNF-α reduced methylation of histone H3 at lysines 9 and 27 (H3K9 and H3K27), well-known residues involved in gene suppression. Inhibition of G9a and EZH2, histone methyltransferases responsible for methylation at H3K9 and H3K27, respectively as well as G9a overexpression demonstrated the involvement of G9a in TNF-α-induced ICAM1 expression and leukocyte adhesion and transmigration. A specific role for KDM4B, a histone demethylase targeting H3K9me2, in TNF-α-induced ICAM1 upregulation was validated with siRNA. Moreover, treating mice with a KDM4 inhibitor ML324 blocked TNF-α-mediated neutrophil adhesion. Similarly, TNF-α-induced VCAM1 expression was suppressed by G9a overexpression and KDM4B knockdown. Collectively, we demonstrated that modification of H3K9me2 by G9a and KDM4B regulates expression of vascular adhesion molecules, and that depletion of these proteins or KDM4B reduces inflammation-induced leukocyte extravasation. Thus, blocking ICAM1 or KDM4B could offer a novel therapeutic opportunity treating brain diseases.
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Affiliation(s)
- Ji-Young Choi
- Department of Nanobiomedical Science & BK21 PLUS NBM Global Research Center for Regenerative Medicine, Dankook University, Cheonan 330-714, South Korea
| | - Sang-Sun Yoon
- Department of Nanobiomedical Science & BK21 PLUS NBM Global Research Center for Regenerative Medicine, Dankook University, Cheonan 330-714, South Korea
| | - Sang-Eun Kim
- Department of Pharmacology, College of Pharmacy, Dankook University, Cheonan 330-714, South Korea
| | - Sangmee Ahn Jo
- Department of Nanobiomedical Science & BK21 PLUS NBM Global Research Center for Regenerative Medicine, Dankook University, Cheonan 330-714, South Korea
- Department of Pharmacology, College of Pharmacy, Dankook University, Cheonan 330-714, South Korea
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345
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Millan MJ. Linking deregulation of non-coding RNA to the core pathophysiology of Alzheimer's disease: An integrative review. Prog Neurobiol 2017; 156:1-68. [PMID: 28322921 DOI: 10.1016/j.pneurobio.2017.03.004] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 03/09/2017] [Accepted: 03/09/2017] [Indexed: 02/06/2023]
Abstract
The human genome encodes a vast repertoire of protein non-coding RNAs (ncRNA), some specific to the brain. MicroRNAs, which interfere with the translation of target mRNAs, are of particular interest since their deregulation has been implicated in neurodegenerative disorders like Alzheimer's disease (AD). However, it remains challenging to link the complex body of observations on miRNAs and AD into a coherent framework. Using extensive graphical support, this article discusses how a diverse panoply of miRNAs convergently and divergently impact (and are impacted by) core pathophysiological processes underlying AD: neuroinflammation and oxidative stress; aberrant generation of β-amyloid-42 (Aβ42); anomalies in the production, cleavage and post-translational marking of Tau; impaired clearance of Aβ42 and Tau; perturbation of axonal organisation; disruption of synaptic plasticity; endoplasmic reticulum stress and the unfolded protein response; mitochondrial dysfunction; aberrant induction of cell cycle re-entry; and apoptotic loss of neurons. Intriguingly, some classes of miRNA provoke these cellular anomalies, whereas others act in a counter-regulatory, protective mode. Moreover, changes in levels of certain species of miRNA are a consequence of the above-mentioned anomalies. In addition to miRNAs, circular RNAs, piRNAs, long non-coding RNAs and other types of ncRNA are being increasingly implicated in AD. Overall, a complex mesh of deregulated and multi-tasking ncRNAs reciprocally interacts with core pathophysiological mechanisms underlying AD. Alterations in ncRNAs can be detected in CSF and the circulation as well as the brain and are showing promise as biomarkers, with the ultimate goal clinical exploitation as targets for novel modes of symptomatic and course-altering therapy.
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Affiliation(s)
- Mark J Millan
- Centre for Therapeutic Innovation in Neuropsychiatry, institut de recherche Servier, 125 chemin de ronde, 78290 Croissy sur Seine, France.
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346
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Astrocytic LRP1 Mediates Brain Aβ Clearance and Impacts Amyloid Deposition. J Neurosci 2017; 37:4023-4031. [PMID: 28275161 DOI: 10.1523/jneurosci.3442-16.2017] [Citation(s) in RCA: 163] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 02/27/2017] [Accepted: 03/02/2017] [Indexed: 11/21/2022] Open
Abstract
Accumulation and deposition of amyloid-β (Aβ) in the brain represent an early and perhaps necessary step in the pathogenesis of Alzheimer's disease (AD). Aβ accumulation leads to the formation of Aβ aggregates, which may directly and indirectly lead to eventual neurodegeneration. While Aβ production is accelerated in many familial forms of early-onset AD, increasing evidence indicates that impaired clearance of Aβ is more evident in late-onset AD. To uncover the mechanisms underlying impaired Aβ clearance in AD, we examined the role of low-density lipoprotein receptor-related protein 1 (LRP1) in astrocytes. Although LRP1 has been shown to play critical roles in brain Aβ metabolism in neurons and vascular mural cells, its role in astrocytes, the most abundant cell type in the brain responsible for maintaining neuronal homeostasis, remains unclear. Here, we show that astrocytic LRP1 plays a critical role in brain Aβ clearance. LRP1 knockdown in primary astrocytes resulted in decreased cellular Aβ uptake and degradation. In addition, silencing of LRP1 in astrocytes led to downregulation of several major Aβ-degrading enzymes, including matrix metalloproteases MMP2, MMP9, and insulin-degrading enzyme. More important, conditional knock-out of the Lrp1 gene in astrocytes in the background of APP/PS1 mice impaired brain Aβ clearance, exacerbated Aβ accumulation, and accelerated amyloid plaque deposition without affecting its production. Together, our results demonstrate that astrocytic LRP1 plays an important role in Aβ metabolism and that restoring LRP1 expression and function in the brain could be an effective strategy to facilitate Aβ clearance and counter amyloid pathology in AD.SIGNIFICANCE STATEMENT Astrocytes represent a major cell type regulating brain homeostasis; however, their roles in brain clearance of amyloid-β (Aβ) and underlying mechanism are not clear. In this study, we used both cellular models and conditional knock-out mouse models to address the role of a critical Aβ receptor, the low-density lipoprotein receptor-related protein 1 (LRP1) in astrocytes. We found that LRP1 in astrocytes plays a critical role in brain Aβ clearance by modulating several Aβ-degrading enzymes and cellular degradation pathways. Our results establish a critical role of astrocytic LRP1 in brain Aβ clearance and shed light on specific Aβ clearance pathways that may help to establish new targets for AD prevention and therapy.
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347
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Graham SH, Liu H. Life and death in the trash heap: The ubiquitin proteasome pathway and UCHL1 in brain aging, neurodegenerative disease and cerebral Ischemia. Ageing Res Rev 2017; 34:30-38. [PMID: 27702698 DOI: 10.1016/j.arr.2016.09.011] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 09/08/2016] [Accepted: 09/29/2016] [Indexed: 12/11/2022]
Abstract
The ubiquitin proteasome pathway (UPP) is essential for removing abnormal proteins and preventing accumulation of potentially toxic proteins within the neuron. UPP dysfunction occurs with normal aging and is associated with abnormal accumulation of protein aggregates within neurons in neurodegenerative diseases. Ischemia disrupts UPP function and thus may contribute to UPP dysfunction seen in the aging brain and in neurodegenerative diseases. Ubiquitin carboxy-terminal hydrolase L1 (UCHL1), an important component of the UPP in the neuron, is covalently modified and its activity inhibited by reactive lipids produced after ischemia. As a result, degradation of toxic proteins is impaired which may exacerbate neuronal function and cell death in stroke and neurodegenerative diseases. Preserving or restoring UCHL1 activity may be an effective therapeutic strategy in stroke and neurodegenerative diseases.
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348
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Graham SH. Introduction to special issue: Neurovascular aging-A driving force for neurological dysfunction in stroke and neurodegenerative diseases. Ageing Res Rev 2017; 34:1-2. [PMID: 27793608 DOI: 10.1016/j.arr.2016.10.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Steven H Graham
- Geriatric Research Educational and Clinical Center, V.A. Pittsburgh Healthcare System, Department of Neurology, University of Pittsburgh, USA.
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349
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Baldassarro VA, Marchesini A, Giardino L, Calzà L. Vulnerability of primary neurons derived from Tg2576 Alzheimer mice to oxygen and glucose deprivation: role of intraneuronal amyloid-β accumulation and astrocytes. Dis Model Mech 2017; 10:671-678. [PMID: 28237964 PMCID: PMC5451168 DOI: 10.1242/dmm.028001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 02/17/2017] [Indexed: 12/12/2022] Open
Abstract
Microvascular dysfunction is considered an integral part of Alzheimer disease (AD) pathogenesis, but the possible relationship between amyloid pathology, microvascular dysfunction and cell death is still unclear. In order to investigate the influence of intraneuronal amyloid-β (Aβ) accumulation on vulnerability to hypoxia, we isolated primary cortical neurons from Tg2576 (carrying the amyloid precursor protein APPSwe mutation) and wild-type fetal mice. We first demonstrated that neurons isolated from Tg2576 newborn mice show an increase in VEGFa mRNA expression and a decrease in the expression of the two VEGF receptors, Flt1 and Kdr, compared with wild-type cells. Moreover, APPSwe primary neurons displayed higher spontaneous and glutamate-induced cell death. We then deprived the cultures of oxygen and glucose (OGD) as an in vitro model of hypoxia. After OGD, APPSwe neurons display higher levels of cell death in terms of percentage of pyknotic/fragmented nuclei and mitochondrial depolarization, accompanied by an increase in the intraneuronal Aβ content. To explore the influence of intraneuronal Aβ peptide accumulation, we used the γ-secretase inhibitor LY450139, which showed that the reduction of the intracellular amyloid fully protects APPSwe neurons from OGD-induced degeneration. Conditioned medium from OGD-exposed APPSwe or wild-type astrocytes protected APPswe neurons but not wild-type neurons, during OGD. In conclusion, the presence of the mutated human APP gene, leading to the intracellular accumulation of APP and Aβ fragments, worsens OGD toxicity. Protection of APPSwe neurons can be obtained either using a γ-secretase inhibitor or astrocyte conditioned medium. Summary:In vitro systems derived from AD mice can be used to investigate the vulnerability of AD neurons to different neurotoxic challenges, including oxygen glucose deprivation.
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Affiliation(s)
- Vito Antonio Baldassarro
- Interdepartmental Centre for Industrial Research in Health Science and Technologies (ICIR - HST), University of Bologna, 40064 Ozzano Emilia, Bologna, Italy.,Department of Pharmacy and Biotechnology (FaBit), University of Bologna, 40127 Bologna, Italy
| | | | - Luciana Giardino
- Interdepartmental Centre for Industrial Research in Health Science and Technologies (ICIR - HST), University of Bologna, 40064 Ozzano Emilia, Bologna, Italy.,Department of Medical Veterinary Sciences (DIMEVET), University of Bologna, 40064 Ozzano Emilia, Bologna, Italy.,Fondazione IRET, 40064 Ozzano Emilia, Bologna, Italy
| | - Laura Calzà
- Interdepartmental Centre for Industrial Research in Health Science and Technologies (ICIR - HST), University of Bologna, 40064 Ozzano Emilia, Bologna, Italy .,Department of Pharmacy and Biotechnology (FaBit), University of Bologna, 40127 Bologna, Italy.,Fondazione IRET, 40064 Ozzano Emilia, Bologna, Italy
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Lee LL, Aung HH, Wilson DW, Anderson SE, Rutledge JC, Rutkowsky JM. Triglyceride-rich lipoprotein lipolysis products increase blood-brain barrier transfer coefficient and induce astrocyte lipid droplets and cell stress. Am J Physiol Cell Physiol 2017; 312:C500-C516. [PMID: 28077357 DOI: 10.1152/ajpcell.00120.2016] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 01/06/2017] [Accepted: 01/09/2017] [Indexed: 12/19/2022]
Abstract
Elevation of blood triglycerides, primarily as triglyceride-rich lipoproteins (TGRL), has been linked to cerebrovascular inflammation, vascular dementia, and Alzheimer's disease (AD). Brain microvascular endothelial cells and astrocytes, two cell components of the neurovascular unit, participate in controlling blood-brain barrier (BBB) permeability and regulating neurovascular unit homeostasis. Our studies showed that infusion of high physiological concentrations of TGRL lipolysis products (TGRL + lipoprotein lipase) activate and injure brain endothelial cells and transiently increase the BBB transfer coefficient (Ki = permeability × surface area/volume) in vivo. However, little is known about how blood lipids affect astrocyte lipid accumulation and inflammation. To address this, we first demonstrated TGRL lipolysis products increased lipid droplet formation in cultured normal human astrocytes. We then evaluated the transcriptional pathways activated in astrocytes by TGRL lipolysis products and found upregulated stress and inflammatory-related genes including activating transcription factor 3 (ATF3), macrophage inflammatory protein-3α (MIP-3α), growth differentiation factor-15 (GDF15), and prostaglandin-endoperoxide synthase 2 (COX2). TGRL lipolysis products also activated the JNK/cJUN/ATF3 pathway, induced endoplasmic reticulum stress protein C/EBP homologous protein (CHOP), and the NF-κB pathway, while increasing secretion of MIP-3α, GDF15, and IL-8. Thus our results demonstrate TGRL lipolysis products increase the BBB transfer coefficient (Ki), induce astrocyte lipid droplet formation, activate cell stress pathways, and induce secretion of inflammatory cytokines. Our observations are consistent with evidence for lipid-induced neurovascular injury and inflammation, and we, therefore, speculate that lipid-induced astrocyte injury could play a role in cognitive decline.
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Affiliation(s)
- Linda L Lee
- Department of Internal Medicine, University of California, Davis, California
| | - Hnin H Aung
- Department of Internal Medicine, University of California, Davis, California
| | - Dennis W Wilson
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, California; and
| | - Steven E Anderson
- Department of Physiology and Membrane Biology, University of California, Davis, California
| | - John C Rutledge
- Department of Internal Medicine, University of California, Davis, California
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