1
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Eisenbaum M, Pearson A, Ortiz C, Mullan M, Crawford F, Ojo J, Bachmeier C. ApoE4 expression disrupts tau uptake, trafficking, and clearance in astrocytes. Glia 2024; 72:184-205. [PMID: 37668005 DOI: 10.1002/glia.24469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 08/07/2023] [Accepted: 08/26/2023] [Indexed: 09/06/2023]
Abstract
Tauopathies are a collection of neurodegenerative diseases characterized by the accumulation of pathogenic aggregates of the microtubule-associated protein tau. Despite the prevalence and diversity of tau astrogliopathy in tauopathies, the interactions between astrocytes and tau in the brain, and the influence of neurodegenerative genetic risk factors like the apolipoprotein E4 (apoE4) isoform, are largely unknown. Here, we leveraged primary and immortalized astrocytes expressing humanized apoE isoforms to characterize the mechanisms by which astrocytes interact with and eliminate extracellular tau, and the influence of apoE genotype on these processes. Our work indicates that astrocytes rapidly internalize, process, and release tau via an exosomal secretory mechanism under physiological conditions. However, we found that apoE4 disrupted these processes in comparison to apoE3, resulting in an astrocytic phenotype prone to intracellular tau accumulation. Furthermore, exposure to repetitive mild traumatic brain injuries exacerbated the apoE4-induced impairments in tau processing and elimination by astrocytes in apoE4 targeted-replacement mice. The diminished ability of apoE4 astrocytes to eliminate extracellular tau can lead to an accumulation of pathogenic tau, which induces mitochondrial dysfunction, as demonstrated by our studies. In total, our findings suggest that the apoE4 isoform lowers the threshold of astrocytic resilience to pathogenic tau, rendering them susceptible to bioenergetic deficits in the early stages of neurodegenerative diseases such as traumatic brain injury, potentially contributing to neurological decline.
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Affiliation(s)
| | | | | | | | - Fiona Crawford
- The Roskamp Institute, Sarasota, Florida, USA
- James A. Haley Veterans' Hospital, Tampa, Florida, USA
| | - Joseph Ojo
- The Roskamp Institute, Sarasota, Florida, USA
| | - Corbin Bachmeier
- The Roskamp Institute, Sarasota, Florida, USA
- Bay Pines VA Healthcare System, Bay Pines, Florida, USA
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2
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Vincow ES, Thomas RE, Milstein G, Pareek G, Bammler T, MacDonald J, Pallanck L. Glucocerebrosidase deficiency leads to neuropathology via cellular immune activation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.13.571406. [PMID: 38168223 PMCID: PMC10760128 DOI: 10.1101/2023.12.13.571406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Mutations in GBA (glucosylceramidase beta), which encodes the lysosomal enzyme glucocerebrosidase (GCase), are the strongest genetic risk factor for the neurodegenerative disorders Parkinson's disease (PD) and Lewy body dementia. Recent work has suggested that neuroinflammation may be an important factor in the risk conferred by GBA mutations. We therefore systematically tested the contributions of immune-related genes to neuropathology in a Drosophila model of GCase deficiency. We identified target immune factors via RNA-Seq and proteomics on heads from GCase-deficient flies, which revealed both increased abundance of humoral factors and increased macrophage activation. We then manipulated the identified immune factors and measured their effect on head protein aggregates, a hallmark of neurodegenerative disease. Genetic ablation of humoral (secreted) immune factors did not suppress the development of protein aggregation. By contrast, re-expressing Gba1b in activated macrophages suppressed head protein aggregation in Gba1b mutants and rescued their lifespan and behavioral deficits. Moreover, reducing the GCase substrate glucosylceramide in activated macrophages also ameliorated Gba1b mutant phenotypes. Taken together, our findings show that glucosylceramide accumulation due to GCase deficiency leads to macrophage activation, which in turn promotes the development of neuropathology.
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Affiliation(s)
- Evelyn S. Vincow
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
| | - Ruth E. Thomas
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
| | - Gillian Milstein
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
| | - Gautam Pareek
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
| | - Theo Bammler
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, United States of America
| | - James MacDonald
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, United States of America
| | - Leo Pallanck
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
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3
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Liu M, Huang J, Liu T, Yuan J, Lv C, Sha Z, Wu C, Jiang W, Liu X, Nie M, Chen Y, Dong S, Qian Y, Gao C, Fan Y, Wu D, Jiang R. Exogenous interleukin 33 enhances the brain's lymphatic drainage and toxic protein clearance in acute traumatic brain injury mice. Acta Neuropathol Commun 2023; 11:61. [PMID: 37024941 PMCID: PMC10080777 DOI: 10.1186/s40478-023-01555-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 03/21/2023] [Indexed: 04/08/2023] Open
Abstract
The persistent dysregulation and accumulation of poisonous proteins from destructive neural tissues and cells activate pathological mechanisms after traumatic brain injury (TBI). The lymphatic drainage system of the brain, composed of the glymphatic system and meningeal lymphatic vessels (MLVs), plays an essential role in the clearance of toxic waste after brain injury. The neuroprotective effect of interleukin 33 (IL-33) in TBI mice has been demonstrated; however, its impact on brain lymphatic drainage is unclear. Here, we established a fluid percussion injury model to examine the IL-33 administration effects on neurological function and lymphatic drainage in the acute brain of TBI mice. We verified that exogenous IL-33 could improve the motor and memory skills of TBI mice and demonstrated that in the acute phase, it increased the exchange of cerebrospinal and interstitial fluid, reversed the dysregulation and depolarization of aquaporin-4 in the cortex and hippocampus, improved the drainage of MLVs to deep cervical lymph nodes, and reduced tau accumulation and glial activation. We speculate that the protective effect of exogenous IL-33 on TBI mice's motor and cognitive functions is related to the enhancement of brain lymphatic drainage and toxic metabolite clearance from the cortex and hippocampus in the acute stage. These data further support the notion that IL-33 therapy may be an effective treatment strategy for alleviating acute brain injury after TBI.
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Affiliation(s)
- Mingqi Liu
- Department of Neurosurgery, Tianjin Medical University General Hospital, 154 Anshan Road, Tianjin, 300052, China
- Tianjin Neurological Institute, Key Laboratory of Post Neuro-Injury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin City, Tianjin, 300052, China
| | - Jinhao Huang
- Department of Neurosurgery, Tianjin Medical University General Hospital, 154 Anshan Road, Tianjin, 300052, China.
- Tianjin Neurological Institute, Key Laboratory of Post Neuro-Injury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin City, Tianjin, 300052, China.
| | - Tao Liu
- Department of Neurosurgery, Tianjin Medical University General Hospital, 154 Anshan Road, Tianjin, 300052, China
- Tianjin Neurological Institute, Key Laboratory of Post Neuro-Injury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin City, Tianjin, 300052, China
| | - Jiangyuan Yuan
- Department of Neurosurgery, Tianjin Medical University General Hospital, 154 Anshan Road, Tianjin, 300052, China
- Tianjin Neurological Institute, Key Laboratory of Post Neuro-Injury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin City, Tianjin, 300052, China
| | - Chuanxiang Lv
- Department of Neurosurgery, The First Clinical Hospital, Jilin University, Changchun, China
| | - Zhuang Sha
- Department of Neurosurgery, Tianjin Medical University General Hospital, 154 Anshan Road, Tianjin, 300052, China
- Tianjin Neurological Institute, Key Laboratory of Post Neuro-Injury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin City, Tianjin, 300052, China
| | - Chenrui Wu
- Department of Neurosurgery, Tianjin Medical University General Hospital, 154 Anshan Road, Tianjin, 300052, China
- Tianjin Neurological Institute, Key Laboratory of Post Neuro-Injury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin City, Tianjin, 300052, China
| | - Weiwei Jiang
- Department of Neurosurgery, Tianjin Medical University General Hospital, 154 Anshan Road, Tianjin, 300052, China
- Tianjin Neurological Institute, Key Laboratory of Post Neuro-Injury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin City, Tianjin, 300052, China
| | - Xuanhui Liu
- Department of Neurosurgery, Tianjin Medical University General Hospital, 154 Anshan Road, Tianjin, 300052, China
- Tianjin Neurological Institute, Key Laboratory of Post Neuro-Injury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin City, Tianjin, 300052, China
| | - Meng Nie
- Department of Neurosurgery, Tianjin Medical University General Hospital, 154 Anshan Road, Tianjin, 300052, China
- Tianjin Neurological Institute, Key Laboratory of Post Neuro-Injury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin City, Tianjin, 300052, China
| | - Yupeng Chen
- Department of Neurosurgery, Tianjin Medical University General Hospital, 154 Anshan Road, Tianjin, 300052, China
- Tianjin Neurological Institute, Key Laboratory of Post Neuro-Injury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin City, Tianjin, 300052, China
| | - Shiying Dong
- Department of Neurosurgery, Tianjin Medical University General Hospital, 154 Anshan Road, Tianjin, 300052, China
- Tianjin Neurological Institute, Key Laboratory of Post Neuro-Injury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin City, Tianjin, 300052, China
| | - Yu Qian
- Department of Neurosurgery, Tianjin Medical University General Hospital, 154 Anshan Road, Tianjin, 300052, China
- Tianjin Neurological Institute, Key Laboratory of Post Neuro-Injury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin City, Tianjin, 300052, China
| | - Chuang Gao
- Department of Neurosurgery, Tianjin Medical University General Hospital, 154 Anshan Road, Tianjin, 300052, China
- Tianjin Neurological Institute, Key Laboratory of Post Neuro-Injury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin City, Tianjin, 300052, China
| | - Yibing Fan
- Department of Neurosurgery, Tianjin First Central Hospital, Tianjin, China
| | - Di Wu
- Department of Neurosurgery, Tianjin Medical University General Hospital, 154 Anshan Road, Tianjin, 300052, China
- Tianjin Neurological Institute, Key Laboratory of Post Neuro-Injury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin City, Tianjin, 300052, China
| | - Rongcai Jiang
- Department of Neurosurgery, Tianjin Medical University General Hospital, 154 Anshan Road, Tianjin, 300052, China.
- Tianjin Neurological Institute, Key Laboratory of Post Neuro-Injury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin City, Tianjin, 300052, China.
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4
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Yan JH, Wang YJ, Sun YR, Pei YH, Ma HW, Mu YK, Qin LH. The lymphatic drainage systems in the brain: a novel target for ischemic stroke? Neural Regen Res 2023; 18:485-491. [DOI: 10.4103/1673-5374.346484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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5
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Abstract
Hypertension affects a significant proportion of the adult and aging population and represents an important risk factor for vascular cognitive impairment and late-life dementia. Chronic high blood pressure continuously challenges the structural and functional integrity of the cerebral vasculature, leading to microvascular rarefaction and dysfunction, and neurovascular uncoupling that typically impairs cerebral blood supply. Hypertension disrupts blood-brain barrier integrity, promotes neuroinflammation, and may contribute to amyloid deposition and Alzheimer pathology. The mechanisms underlying these harmful effects are still a focus of investigation, but studies in animal models have provided significant molecular and cellular mechanistic insights. Remaining questions relate to whether adequate treatment of hypertension may prevent deterioration of cognitive function, the threshold for blood pressure treatment, and the most effective antihypertensive drugs. Recent advances in neurovascular biology, advanced brain imaging, and detection of subtle behavioral phenotypes have begun to provide insights into these critical issues. Importantly, a parallel analysis of these parameters in animal models and humans is feasible, making it possible to foster translational advancements. In this review, we provide a critical evaluation of the evidence available in experimental models and humans to examine the progress made and identify remaining gaps in knowledge.
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Affiliation(s)
| | - Costantino Iadecola
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY
| | - Daniela Carnevale
- Department of Molecular Medicine, “Sapienza” University of Rome, Italy
- Research Unit of Neuro and Cardiovascular Pathophysiology, IRCCS Neuromed, Pozzilli, Italy
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6
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Hier DB, Azizi S, Thimgan MS, Wunsch DC. Tau kinetics in Alzheimer's disease. Front Aging Neurosci 2022; 14:1055170. [PMID: 36437992 PMCID: PMC9682289 DOI: 10.3389/fnagi.2022.1055170] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 10/27/2022] [Indexed: 07/20/2023] Open
Abstract
The cytoskeletal protein tau is implicated in the pathogenesis of Alzheimer's disease which is characterized by intra-neuronal neurofibrillary tangles containing abnormally phosphorylated insoluble tau. Levels of soluble tau are elevated in the brain, the CSF, and the plasma of patients with Alzheimer's disease. To better understand the causes of these elevated levels of tau, we propose a three-compartment kinetic model (brain, CSF, and plasma). The model assumes that the synthesis of tau follows zero-order kinetics (uncorrelated with compartmental tau levels) and that the release, absorption, and clearance of tau is governed by first-order kinetics (linearly related to compartmental tau levels). Tau that is synthesized in the brain compartment can be released into the interstitial fluid, catabolized, or retained in neurofibrillary tangles. Tau released into the interstitial fluid can mix with the CSF and eventually drain to the plasma compartment. However, losses of tau in the drainage pathways may be significant. The kinetic model estimates half-life of tau in each compartment (552 h in the brain, 9.9 h in the CSF, and 10 h in the plasma). The kinetic model predicts that an increase in the neuronal tau synthesis rate or a decrease in tau catabolism rate best accounts for observed increases in tau levels in the brain, CSF, and plasma found in Alzheimer's disease. Furthermore, the model predicts that increases in brain half-life of tau in Alzheimer's disease should be attributed to decreased tau catabolism and not to increased tau synthesis. Most clearance of tau in the neuron occurs through catabolism rather than release to the CSF compartment. Additional experimental data would make ascertainment of the model parameters more precise.
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Affiliation(s)
- Daniel B. Hier
- Applied Computational Intelligence Laboratory, Department of Electrical & Computer Engineering, Missouri University of Science & Technology, Rolla, MO, United States
- Department of Neurology and Rehabilitation, University of Illinois at Chicago, Chicago, IL, United States
| | - Sima Azizi
- Applied Computational Intelligence Laboratory, Department of Electrical & Computer Engineering, Missouri University of Science & Technology, Rolla, MO, United States
| | - Matthew S. Thimgan
- Department of Biological Sciences, Missouri University of Science & Technology, Rolla, MO, United States
| | - Donald C. Wunsch
- Applied Computational Intelligence Laboratory, Department of Electrical & Computer Engineering, Missouri University of Science & Technology, Rolla, MO, United States
- ECCS Division, National Science Foundation, Alexandria, VA, United States
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7
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Zhao L, Tannenbaum A, Bakker ENTP, Benveniste H. Physiology of Glymphatic Solute Transport and Waste Clearance from the Brain. Physiology (Bethesda) 2022; 37:0. [PMID: 35881783 PMCID: PMC9550574 DOI: 10.1152/physiol.00015.2022] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 07/12/2022] [Accepted: 07/20/2022] [Indexed: 12/25/2022] Open
Abstract
This review focuses on the physiology of glymphatic solute transport and waste clearance, using evidence from experimental animal models as well as from human studies. Specific topics addressed include the biophysical characteristics of fluid and solute transport in the central nervous system, glymphatic-lymphatic coupling, as well as the role of cerebrospinal fluid movement for brain waste clearance. We also discuss the current understanding of mechanisms underlying increased waste clearance during sleep.
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Affiliation(s)
- Lucy Zhao
- Department of Anesthesiology, Yale School of Medicine, New Haven, Connecticut
| | - Allen Tannenbaum
- Departments of Computer Science and Applied Mathematics and Statistics, Stony Brook University, Stony Brook, New York
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York City, New York
| | - Erik N T P Bakker
- Department of Biomedical Engineering and Physics, Amsterdam UMC, Amsterdam Cardiovascular Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Helene Benveniste
- Department of Anesthesiology, Yale School of Medicine, New Haven, Connecticut
- Department of Biomedical Engineering, Yale School of Medicine, New Haven, Connecticut
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8
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Sturmey E, Malaspina A. Blood biomarkers in ALS: challenges, applications and novel frontiers. Acta Neurol Scand 2022; 146:375-388. [PMID: 36156207 PMCID: PMC9828487 DOI: 10.1111/ane.13698] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 08/15/2022] [Accepted: 08/19/2022] [Indexed: 01/12/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease among adults. With diagnosis reached relatively late into the disease process, extensive motor cell loss narrows the window for therapeutic opportunities. Clinical heterogeneity in ALS and the lack of disease-specific biomarkers have so far led to large-sized clinical trials with long follow-up needed to define clinical outcomes. In advanced ALS patients, there is presently limited scope to use imaging or invasive cerebrospinal fluid (CSF) collection as a source of disease biomarkers. The development of more patient-friendly and accessible blood biomarker assays is hampered by analytical hurdles like the matrix effect of blood components. However, blood also provides the opportunity to identify disease-specific adaptive changes of the stoichiometry and conformation of target proteins and the endogenous immunological response to low-abundance brain peptides, such as neurofilaments (Nf). Among those biomarkers under investigation in ALS, the change in concentration before or after diagnosis of Nf has been shown to aid prognostication and to allow the a priori stratification of ALS patients into smaller sized and clinically more homogeneous cohorts, supporting more affordable clinical trials. Here, we discuss the technical hurdles affecting reproducible and sensitive biomarker measurement in blood. We also summarize the state of the art of non-CSF biomarkers in the study of prognosis, disease progression, and treatment response. We will then address the potential as disease-specific biomarkers of the newly discovered cryptic peptides which are formed down-stream of TDP-43 loss of function, the hallmark of ALS pathobiology.
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Affiliation(s)
- Ellie Sturmey
- Centre of Neuroscience, Surgery and Trauma, Queen Mary University of London, London, UK
| | - Andrea Malaspina
- Centre of Neuroscience, Surgery and Trauma, Queen Mary University of London, London, UK.,Queen Square Institute of Neurology, University College London, London, UK
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9
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Eisenbaum M, Pearson A, Gratkowski A, Mouzon B, Mullan M, Crawford F, Ojo J, Bachmeier C. Influence of traumatic brain injury on extracellular tau elimination at the blood-brain barrier. Fluids Barriers CNS 2021; 18:48. [PMID: 34702292 PMCID: PMC8549249 DOI: 10.1186/s12987-021-00283-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 10/18/2021] [Indexed: 03/14/2023] Open
Abstract
Repetitive head trauma has been associated with the accumulation of tau species in the brain. Our prior work showed brain vascular mural cells contribute to tau processing in the brain, and that these cells progressively degenerate following repetitive mild traumatic brain injury (r-mTBI). The current studies investigated the role of the cerebrovasculature in the elimination of extracellular tau from the brain, and the influence of r-mTBI on these processes. Following intracranial injection of biotin-labeled tau, the levels of exogenous labeled tau residing in the brain were elevated in a mouse model of r-mTBI at 12 months post-injury compared to r-sham mice, indicating reduced tau elimination from the brain following head trauma. This may be the result of decreased caveolin-1 mediated tau efflux at the blood–brain barrier (BBB), as the caveolin inhibitor, methyl-β-cyclodextrin, significantly reduced tau uptake in isolated cerebrovessels and significantly decreased the basolateral-to-apical transit of tau across an in vitro model of the BBB. Moreover, we found that the upstream regulator of endothelial caveolin-1, Mfsd2a, was elevated in r-mTBI cerebrovessels compared to r-sham, which coincided with a decreased expression of cerebrovascular caveolin-1 in the chronic phase following r-mTBI (> 3 months post-injury). Lastly, angiopoietin-1, a mural cell-derived protein governing endothelial Mfsd2a expression, was secreted from r-mTBI cerebrovessels to a greater extent than r-sham animals. Altogether, in the chronic phase post-injury, release of angiopoietin-1 from degenerating mural cells downregulates caveolin-1 expression in brain endothelia, resulting in decreased tau elimination across the BBB, which may describe the accumulation of tau species in the brain following head trauma.
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Affiliation(s)
- Maxwell Eisenbaum
- The Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL, 34243, USA. .,The Open University, Milton Keynes, UK.
| | - Andrew Pearson
- The Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL, 34243, USA.,The Open University, Milton Keynes, UK
| | - Arissa Gratkowski
- The Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL, 34243, USA
| | - Benoit Mouzon
- The Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL, 34243, USA.,The Open University, Milton Keynes, UK.,James A. Haley Veterans' Hospital, Tampa, FL, USA
| | - Michael Mullan
- The Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL, 34243, USA.,The Open University, Milton Keynes, UK
| | - Fiona Crawford
- The Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL, 34243, USA.,The Open University, Milton Keynes, UK.,James A. Haley Veterans' Hospital, Tampa, FL, USA
| | - Joseph Ojo
- The Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL, 34243, USA.,The Open University, Milton Keynes, UK
| | - Corbin Bachmeier
- The Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL, 34243, USA.,The Open University, Milton Keynes, UK.,Bay Pines VA Healthcare System, Bay Pines, FL, USA
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10
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Hier DB, Obafemi-Ajayi T, Thimgan MS, Olbricht GR, Azizi S, Allen B, Hadi BA, Wunsch DC. Blood biomarkers for mild traumatic brain injury: a selective review of unresolved issues. Biomark Res 2021; 9:70. [PMID: 34530937 PMCID: PMC8447604 DOI: 10.1186/s40364-021-00325-5] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 08/26/2021] [Indexed: 01/03/2023] Open
Abstract
Background The use of blood biomarkers after mild traumatic brain injury (mTBI) has been widely studied. We have identified eight unresolved issues related to the use of five commonly investigated blood biomarkers: neurofilament light chain, ubiquitin carboxy-terminal hydrolase-L1, tau, S100B, and glial acidic fibrillary protein. We conducted a focused literature review of unresolved issues in three areas: mode of entry into and exit from the blood, kinetics of blood biomarkers in the blood, and predictive capacity of the blood biomarkers after mTBI. Findings Although a disruption of the blood brain barrier has been demonstrated in mild and severe traumatic brain injury, biomarkers can enter the blood through pathways that do not require a breach in this barrier. A definitive accounting for the pathways that biomarkers follow from the brain to the blood after mTBI has not been performed. Although preliminary investigations of blood biomarkers kinetics after TBI are available, our current knowledge is incomplete and definitive studies are needed. Optimal sampling times for biomarkers after mTBI have not been established. Kinetic models of blood biomarkers can be informative, but more precise estimates of kinetic parameters are needed. Confounding factors for blood biomarker levels have been identified, but corrections for these factors are not routinely made. Little evidence has emerged to date to suggest that blood biomarker levels correlate with clinical measures of mTBI severity. The significance of elevated biomarker levels thirty or more days following mTBI is uncertain. Blood biomarkers have shown a modest but not definitive ability to distinguish concussed from non-concussed subjects, to detect sub-concussive hits to the head, and to predict recovery from mTBI. Blood biomarkers have performed best at distinguishing CT scan positive from CT scan negative subjects after mTBI.
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Affiliation(s)
- Daniel B Hier
- Department of Electrical and Computer Engineering, Missouri University of Science and Technology, Rolla, MO 65401, USA.
| | - Tayo Obafemi-Ajayi
- Cooperative Engineering Program, Missouri State University, Springfield, MO 65897, United States
| | - Matthew S Thimgan
- Department of Biological Sciences, Missouri University of Science and Technology, Rolla, MO 65409, United States
| | - Gayla R Olbricht
- Department of Mathematics and Statistics, Missouri University of Science and Technology, Rolla, MO 65409, United States
| | - Sima Azizi
- Department of Electrical and Computer Engineering, Missouri University of Science and Technology, Rolla, MO 65401, USA
| | - Blaine Allen
- Department of Electrical and Computer Engineering, Missouri University of Science and Technology, Rolla, MO 65401, USA
| | - Bassam A Hadi
- Department of Surgery, Mercy Hospital, St. Louis MO, Missouri, MO 63141, United States
| | - Donald C Wunsch
- Department of Electrical and Computer Engineering, Missouri University of Science and Technology, Rolla, MO 65401, USA.,National Science Foundation, ECCS Division, Virginia, 22314, USA
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11
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Bèchet NB, Shanbhag NC, Lundgaard I. Glymphatic pathways in the gyrencephalic brain. J Cereb Blood Flow Metab 2021; 41:2264-2279. [PMID: 33641515 PMCID: PMC8393296 DOI: 10.1177/0271678x21996175] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 01/22/2021] [Accepted: 01/28/2021] [Indexed: 01/11/2023]
Abstract
Identification of the perivascular compartment as the point of exchange between cerebrospinal fluid (CSF) and interstitial fluid mediating solute clearance in the brain, named the glymphatic system, has emerged as an important clearance pathway for neurotoxic peptides such as amyloid-beta. However, the foundational science of the glymphatic system is based on rodent studies. Here we investigated whether the glymphatic system exists in a large mammal with a highly gyrified brain. CSF penetration into the brain via perivascular pathways, a hallmark of glymphatic function, was seen throughout the gyrencephalic cortex and subcortical structures, validating the conservation of the glymphatic system in a large mammal. Macroscopic CSF tracer distribution followed the sulci and fissures showing that these folds enhance CSF dispersion. Three-dimensional renditions from light sheet microscopy showed a PVS influx density 4-fold larger in the pig brain than in mice. This demonstrates the existence of an advanced solute transport system in the gyrencephalic brain that could be utilised therapeutically for enhancing waste clearance.
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Affiliation(s)
- Nicholas Burdon Bèchet
- Department of Experimental Medical Science, Lund University, Lund, Sweden
- Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden
| | - Nagesh C Shanbhag
- Department of Experimental Medical Science, Lund University, Lund, Sweden
- Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden
| | - Iben Lundgaard
- Department of Experimental Medical Science, Lund University, Lund, Sweden
- Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden
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12
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Wafford KA. Aberrant waste disposal in neurodegeneration: why improved sleep could be the solution. CEREBRAL CIRCULATION - COGNITION AND BEHAVIOR 2021; 2:100025. [PMID: 36324713 PMCID: PMC9616228 DOI: 10.1016/j.cccb.2021.100025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 08/11/2021] [Accepted: 08/12/2021] [Indexed: 06/16/2023]
Abstract
Sleep takes up a large percentage of our lives and the full functions of this state are still not understood. However, over the last 10 years a new and important function has emerged as a mediator of brain clearance. Removal of toxic metabolites and proteins from the brain parenchyma generated during waking activity and high levels of synaptic processing is critical to normal brain function and only enabled during deep sleep. Understanding of this process is revealing how impaired sleep contributes an important and likely causative role in the accumulation and aggregation of aberrant proteins such as β-amyloid and phosphorylated tau, as well as inflammation and neuronal damage. We are also beginning to understand how brain slow-wave activity interacts with vascular function allowing the flow of CSF and interstitial fluid to drain into the body's lymphatic system. New methodology is enabling visualization of this process in both animals and humans and is revealing how these processes break down during ageing and disease. With this understanding we can begin to envisage novel therapeutic approaches to the treatment of neurodegeneration, and how reversing sleep impairment in the correct manner may provide a way to slow these processes and improve brain function.
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Key Words
- AQP4, aquaporin-4
- Alzheimer's disease
- Amyloid
- Aquaporin-4
- Astrocyte
- Aβ, beta amyloid
- BOLD, blood-oxygen level dependent imaging
- CAA, cerebral amyloid angiopathy
- CSF, Cerebrospinal fluid
- Clearance
- EEG, electroencephalography
- EMG, electromyography
- Glymphatic
- ISF, interstitial fluid
- MCI, mild cognitive impairment
- MRI, magnetic resonance imaging
- NOS, nitric oxide synthase
- NREM, non-rapid eye movement
- OSA, obstructive sleep apnea
- PET, positron emission tomography
- REM, rapid-eye movement
- SWA, slow wave activity
- SWS, slow-wave sleep
- Slow-wave sleep
- iNPH, idiopathic normal pressure hydrocephalus
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Azizi S, Hier DB, Allen B, Obafemi-Ajayi T, Olbricht GR, Thimgan MS, Wunsch DC. A Kinetic Model for Blood Biomarker Levels After Mild Traumatic Brain Injury. Front Neurol 2021; 12:668606. [PMID: 34295300 PMCID: PMC8289906 DOI: 10.3389/fneur.2021.668606] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 06/09/2021] [Indexed: 01/23/2023] Open
Abstract
Traumatic brain injury (TBI) imposes a significant economic and social burden. The diagnosis and prognosis of mild TBI, also called concussion, is challenging. Concussions are common among contact sport athletes. After a blow to the head, it is often difficult to determine who has had a concussion, who should be withheld from play, if a concussed athlete is ready to return to the field, and which concussed athlete will develop a post-concussion syndrome. Biomarkers can be detected in the cerebrospinal fluid and blood after traumatic brain injury and their levels may have prognostic value. Despite significant investigation, questions remain as to the trajectories of blood biomarker levels over time after mild TBI. Modeling the kinetic behavior of these biomarkers could be informative. We propose a one-compartment kinetic model for S100B, UCH-L1, NF-L, GFAP, and tau biomarker levels after mild TBI based on accepted pharmacokinetic models for oral drug absorption. We approximated model parameters using previously published studies. Since parameter estimates were approximate, we did uncertainty and sensitivity analyses. Using estimated kinetic parameters for each biomarker, we applied the model to an available post-concussion biomarker dataset of UCH-L1, GFAP, tau, and NF-L biomarkers levels. We have demonstrated the feasibility of modeling blood biomarker levels after mild TBI with a one compartment kinetic model. More work is needed to better establish model parameters and to understand the implications of the model for diagnostic use of these blood biomarkers for mild TBI.
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Affiliation(s)
- Sima Azizi
- Applied Computational Intelligence Laboratory, Department of Electrical and Computer Engineering, Missouri University of Science and Technology, Rolla, MO, United States
| | - Daniel B Hier
- Applied Computational Intelligence Laboratory, Department of Electrical and Computer Engineering, Missouri University of Science and Technology, Rolla, MO, United States
| | - Blaine Allen
- Applied Computational Intelligence Laboratory, Department of Electrical and Computer Engineering, Missouri University of Science and Technology, Rolla, MO, United States
| | - Tayo Obafemi-Ajayi
- Engineering Program, Missouri State University, Springfield, MO, United States
| | - Gayla R Olbricht
- Department of Mathematics and Statistics, Missouri University of Science and Technology, Rolla, MO, United States
| | - Matthew S Thimgan
- Department of Biological Sciences, Missouri University of Science and Technology, Rolla, MO, United States
| | - Donald C Wunsch
- Applied Computational Intelligence Laboratory, Department of Electrical and Computer Engineering, Missouri University of Science and Technology, Rolla, MO, United States.,ECCS Division, National Science Foundation, Alexandria, VA, United States
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Nimmo J, Johnston DA, Dodart JC, MacGregor-Sharp MT, Weller RO, Nicoll JAR, Verma A, Carare RO. Peri-arterial pathways for clearance of α-Synuclein and tau from the brain: Implications for the pathogenesis of dementias and for immunotherapy. ALZHEIMER'S & DEMENTIA: DIAGNOSIS, ASSESSMENT & DISEASE MONITORING 2020; 12:e12070. [PMID: 32782922 PMCID: PMC7409108 DOI: 10.1002/dad2.12070] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 06/22/2020] [Accepted: 06/22/2020] [Indexed: 12/11/2022]
Abstract
Introduction Accumulation of amyloid beta (Aβ), α-synuclein (αSyn), and tau in dementias indicates their age-related failure of elimination from the brain. Aβ is eliminated along basement membranes in walls of cerebral arterioles and leptomeningeal arteries (intramural peri-arterial drainage [IPAD]); IPAD is impaired with age. We test the hypothesis that αSyn and tau are also eliminated from the normal brain along IPAD pathways. Methods Soluble αSyn or tau was injected into mouse hippocampus. Animals were perfused 5 minutes to 7 days post-injection. Blood vessels were identified by ROX-SE for light-sheet and immunolabeling for confocal microscopy. IPAD was quantified by measuring the proportion of arterioles with αSyn/tau. Results αSyn and tau are eliminated from the brain by IPAD but with different dynamics. Discussion Age-related failure of IPAD may play a role in the pathogenesis of synucleinopathies and tauopathies. αSyn persists within IPAD at 24 hours, which may affect immunotherapy for αSyn.
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Affiliation(s)
- Jacqui Nimmo
- Faculty of Medicine University of Southampton Southampton UK
| | | | - J C Dodart
- United Neuroscience Dublin Republic of Ireland
| | | | - Roy O Weller
- Faculty of Medicine University of Southampton Southampton UK
| | | | - Ajay Verma
- United Neuroscience Dublin Republic of Ireland
| | - Roxana O Carare
- Faculty of Medicine University of Southampton Southampton UK
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