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Eisenbaum M, Bachmeier C. Contribution of astrocytes to the neurovascular elimination of tau. Neural Regen Res 2024; 19:2559-2560. [PMID: 38808980 DOI: 10.4103/nrr.nrr-d-23-01705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 01/25/2024] [Indexed: 05/30/2024] Open
Affiliation(s)
| | - Corbin Bachmeier
- The Roskamp Institute, Sarasota, FL, USA (Eisenbaum M, Bachmeier C)
- Bay Pines VA Healthcare System, Bay Pines, FL, USA (Bachmeier C)
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Dallmeier JD, Gober R, Vontell RT, Barreda A, Dorfsman DA, Davis DA, Sun X, Brzostowicki D, Bennett I, Garamszegi SP, Wander CM, Cohen T, Scott WK. Corpora amylacea negatively correlate with hippocampal tau pathology in Alzheimer's disease. Front Neurosci 2024; 18:1286924. [PMID: 38486969 PMCID: PMC10937356 DOI: 10.3389/fnins.2024.1286924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 02/19/2024] [Indexed: 03/17/2024] Open
Abstract
Introduction Severity and distribution of aggregated tau and neurofibrillary tangles (NFT) are strongly correlated with the clinical presentation of Alzheimer's disease (AD). Clearance of aggregated tau could decrease the rate of NFT formation and delay AD onset. Recent studies implicate corpora amylacea (CA) as a regulator of onset or accumulation of tau pathology. Normally, CA clear brain waste products by amassing cellular debris, which are then extruded into the cerebrospinal fluid to be phagocytosed. The proper functioning of CA may slow progression of AD-associated NFT pathology, and this relationship may be influenced by amount and distribution of phospho-tau (pTau) produced, age, sex, and genetic risk. Objective The goal of this study was to determine if CA size and number are associated with hippocampal location and local pTau severity while accounting for variations in age, sex, and genetic risk. Methods Postmortem brain hippocampal tissue sections from 40 AD and 38 unaffected donors were immunohistochemically stained with AT8 (pTau) and counter stained with periodic acid Schiff (PAS). Stained sections of the CA1 and CA3 regions of the hippocampus were analyzed. The percent area occupied (%AO) of CA, pTau, and NFT was calculated. Pairwise comparisons and regression modeling were used to analyze the influence of age, pTau %AO, and genetic risk on %AO by CA in each region, separately in donors with AD and unaffected donors. Results CA %AO was significantly higher in the CA3 region compared to CA1 in both groups. A significant negative correlation of CA %AO with both pTau %AO and neurofibrillary tangle %AO in the CA3 region of AD brain donors was found. Regression analysis in the CA3 region revealed a significant negative association between CA with both pTau and age. Conclusion We found an increase of CA in the CA3 region, compared to CA1 region, in AD and unaffected donors. This may suggest that the CA3 region is a hub for waste removal. Additionally, the negative correlation between %AO by CA and NFT in the CA3 region of the hippocampus in donors with AD suggests CA could play a role in AD pathologic progression by influencing tau clearance.
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Affiliation(s)
- Julian D. Dallmeier
- Brain Endowment Bank, Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Ryan Gober
- Brain Endowment Bank, Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Regina T. Vontell
- Brain Endowment Bank, Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, United States
- Department of Neurology, Evelyn F. McKnight Brain Institute, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Ayled Barreda
- Brain Endowment Bank, Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Daniel A. Dorfsman
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, United States
| | - David A. Davis
- Brain Endowment Bank, Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, United States
- Department of Neurology, Evelyn F. McKnight Brain Institute, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Xiaoyan Sun
- Brain Endowment Bank, Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, United States
- Department of Neurology, Evelyn F. McKnight Brain Institute, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Daniel Brzostowicki
- Brain Endowment Bank, Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Illiana Bennett
- Brain Endowment Bank, Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Susanna P. Garamszegi
- Brain Endowment Bank, Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Connor M. Wander
- Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Todd Cohen
- Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - William K. Scott
- Brain Endowment Bank, Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, United States
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, United States
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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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Tseng JH, Cohen TJ. The emerging nontraditional roles for tau in the brain. Cytoskeleton (Hoboken) 2024; 81:89-94. [PMID: 38063261 PMCID: PMC11068308 DOI: 10.1002/cm.21811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Revised: 11/02/2023] [Accepted: 11/15/2023] [Indexed: 01/24/2024]
Affiliation(s)
- Jui-Heng Tseng
- Arizona State University-Banner Neurodegenerative Disease Research Center at the Biodesign Institute, Tempe, AZ 85287, USA
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - Todd J. Cohen
- UNC Neuroscience Center, University of North Carolina, Chapel Hill, NC 27599, USA
- Department of Neurology, University of North Carolina, Chapel Hill, NC 27599, USA
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Riew TR, Hwang JW, Jin X, Kim HL, Jung SJ, Lee MY. Astrocytes are involved in the formation of corpora amylacea-like structures from neuronal debris in the CA1 region of the rat hippocampus after ischemia. Front Cell Neurosci 2023; 17:1308247. [PMID: 38188667 PMCID: PMC10766773 DOI: 10.3389/fncel.2023.1308247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 12/04/2023] [Indexed: 01/09/2024] Open
Abstract
Recently, we demonstrated that the corpora amylacea (CA), a glycoprotein-rich aggregate frequently found in aged brains, accumulates in the ischemic hippocampus and that osteopontin (OPN) mediates the entire process of CA formation. Therefore, this study aimed to elucidate the mechanisms by which astrocytes and microglia participate in CA formation during the late phase (4-12 weeks) of brain ischemia. Based on various morphological analyses, including immunohistochemistry, in situ hybridization, immunoelectron microscopy, and correlative light and electron microscopy, we propose that astrocytes are the primary cells responsible for CA formation after ischemia. During the subacute phase after ischemia, astrocytes, rather than microglia, express Opn messenger ribonucleic acid and OPN protein, a surrogate marker and key component of CA. Furthermore, the specific localization of OPN in the Golgi complex suggests that it is synthesized and secreted by astrocytes. Astrocytes were in close proximity to type I OPN deposits, which accumulated in the mitochondria of degenerating neurons before fully forming the CA (type III OPN deposits). Throughout CA formation, astrocytes remained closely attached to OPN deposits, with their processes exhibiting well-developed gap junctions. Astrocytic cytoplasmic protein S100β, a calcium-binding protein, was detected within the fully formed CA. Additionally, ultrastructural analysis revealed direct contact between astroglial fibrils and the forming facets of the CA. Overall, we demonstrated that astrocytes play a central role in mediating CA formation from the initial stages of OPN deposit accumulation to the evolution of fully formed CA following transient ischemia in the hippocampus.
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Affiliation(s)
- Tae-Ryong Riew
- Department of Anatomy, Catholic Neuroscience Institute, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
- Department of Biomedicine and Health Sciences, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Ji-Won Hwang
- Department of Anatomy, Catholic Neuroscience Institute, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
- Department of Biomedicine and Health Sciences, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Xuyan Jin
- Department of Anatomy, Catholic Neuroscience Institute, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
- Department of Biomedicine and Health Sciences, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Hong Lim Kim
- Integrative Research Support Center, Laboratory of Electron Microscope, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Sharon Jiyoon Jung
- Technological Convergence Center, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
| | - Mun-Yong Lee
- Department of Anatomy, Catholic Neuroscience Institute, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
- Department of Biomedicine and Health Sciences, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
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Gumber S, Connor-Stroud F, Howard D, Zhang X, Bradley BJ, Sherwood CC, Walker LC. Polyglucosan body disease in an aged chimpanzee (Pan troglodytes). Neuropathology 2023; 43:463-471. [PMID: 37086019 PMCID: PMC10642523 DOI: 10.1111/neup.12906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 03/31/2023] [Accepted: 04/04/2023] [Indexed: 04/23/2023]
Abstract
A 57-year-old female chimpanzee presented with a brief history of increasing lethargy and rapidly progressive lower-limb weakness that culminated in loss of use. Postmortem examination revealed no significant gross lesions in the nervous system or other organ systems. Histological analysis revealed round, basophilic to amphophilic polyglucosan bodies (PGBs) in the white and gray matter of the cervical, thoracic, lumbar, and coccygeal regions of spinal cord. Only rare PGBs were observed in forebrain samples. The lesions in the spinal cord were polymorphic, and they were positively stained with hematoxylin, periodic acid Schiff, Alcian blue, toluidine blue, Bielschowsky silver, and Grocott-Gomori methenamine-silver methods, and they were negative for von Kossa and Congo Red stains. Immunohistochemical evaluation revealed reactivity with antibodies to ubiquitin, but they were negative for glial fibrillary acidic protein, neuron-specific enolase, neurofilaments, tau protein, and Aβ protein. Electron microscopy revealed non-membrane-bound deposits composed of densely packed filaments within axons and in the extracellular space. Intra-axonal PGBs were associated with disruption of the axonal fine structure and disintegration of the surrounding myelin sheath. These findings are the first description of PGBs linked to neurological dysfunction in a chimpanzee. Clinicopathologically, the disorder resembled adult PGB disease in humans.
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Affiliation(s)
- Sanjeev Gumber
- Division of Pathology, Emory National Primate Research Center, Emory University, Atlanta, GA, 30329, USA
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Fawn Connor-Stroud
- Division of Veterinary Medicine, Emory National Primate Research Center, Emory University, Atlanta, GA, 30329, USA
| | - Dustin Howard
- Center for the Advanced Study of Human Paleobiology, Department of Anthropology, The George Washington University, Washington, DC, 20052, USA
| | - Xiaodong Zhang
- Emory Primate Center Imaging Center, Emory National Primate Research Center, Emory University, Atlanta, GA, 30329, USA
| | - Brenda J. Bradley
- Center for the Advanced Study of Human Paleobiology, Department of Anthropology, The George Washington University, Washington, DC, 20052, USA
| | - Chet C. Sherwood
- Center for the Advanced Study of Human Paleobiology, Department of Anthropology, The George Washington University, Washington, DC, 20052, USA
| | - Lary C. Walker
- Division of Neuropharmacology and Neurologic Diseases, Emory National Primate Research Center, Emory University, Atlanta, GA, 30329, USA
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, 30322, USA
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Lee JY, Mack AF, Mattheus U, Donato S, Longo R, Tromba G, Shiozawa T, Scheffler K, Hagberg GE. Distribution of corpora amylacea in the human midbrain: using synchrotron radiation phase-contrast microtomography, high-field magnetic resonance imaging, and histology. Front Neurosci 2023; 17:1236876. [PMID: 37869518 PMCID: PMC10586329 DOI: 10.3389/fnins.2023.1236876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Accepted: 09/06/2023] [Indexed: 10/24/2023] Open
Abstract
Corpora amylacea (CA) are polyglucosan aggregated granules that accumulate in the human body throughout aging. In the cerebrum, CA have been found in proximity to ventricular walls, pial surfaces, and blood vessels. However, studies showing their three-dimensional spatial distribution are sparse. In this study, volumetric images of four human brain stems were obtained with MRI and phase-contrast X-ray microtomography, followed up by Periodic acid Schiff stain for validation. CA appeared as hyperintense spheroid structures with diameters up to 30 μm. An automatic pipeline was developed to segment the CA, and the spatial distribution of over 200,000 individual corpora amylacea could be investigated. A threefold-or higher-density of CA was detected in the dorsomedial column of the periaqueductal gray (860-4,200 CA count/mm3) than in the superior colliculus (150-340 CA count/mm3). We estimated that about 2% of the CA were located in the immediate vicinity of the vessels or in the peri-vascular space. While CA in the ependymal lining of the cerebral aqueduct was rare, the sub-pial tissue of the anterior and posterior midbrain contained several CA. In the sample with the highest CA density, quantitative maps obtained with MRI revealed high R2* values and a diamagnetic shift in a region which spatially coincided with the CA dense region.
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Affiliation(s)
- Ju Young Lee
- Graduate Training Centre of Neuroscience, Eberhard Karl's University of Tübingen, Tübingen, Germany
- High Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
| | - Andreas F. Mack
- Institute of Clinical Anatomy and Cell Analysis, Eberhard Karl's University of Tübingen, Tübingen, Germany
| | - Ulrich Mattheus
- Institute of Clinical Anatomy and Cell Analysis, Eberhard Karl's University of Tübingen, Tübingen, Germany
| | - Sandro Donato
- Department of Physics and STAR-LAB, University of Calabria, Rende, Italy
- Division of Frascati, Istituto Nazionale di Fisica Nucleare (INFN), Frascati, Italy
| | - Renata Longo
- Department of Physics, University of Trieste, Trieste, Italy
- Division of Trieste, Istituto Nazionale di Fisica Nucleare (INFN), Trieste, Italy
| | | | - Thomas Shiozawa
- Institute of Clinical Anatomy and Cell Analysis, Eberhard Karl's University of Tübingen, Tübingen, Germany
| | - Klaus Scheffler
- High Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
- Department of Biomedical Magnetic Resonance, University Hospital Tübingen, Tübingen, Germany
| | - Gisela E. Hagberg
- High Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
- Department of Biomedical Magnetic Resonance, University Hospital Tübingen, Tübingen, Germany
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Riba M, del Valle J, Romera C, Alsina R, Molina-Porcel L, Pelegrí C, Vilaplana J. Uncovering tau in wasteosomes (corpora amylacea) of Alzheimer’s disease patients. Front Aging Neurosci 2023; 15:1110425. [PMID: 37065464 PMCID: PMC10101234 DOI: 10.3389/fnagi.2023.1110425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 03/14/2023] [Indexed: 04/01/2023] Open
Abstract
Brain corpora amylacea, recently renamed as wasteosomes, are polyglucosan bodies that appear during aging and some neurodegenerative conditions. They collect waste substances and are part of a brain cleaning mechanism. For decades, studies on their composition have produced inconsistent results and the presence of tau protein in them has been controversial. In this work, we reanalyzed the presence of this protein in wasteosomes and we pointed out a methodological problem when immunolabeling. It is well known that to detect tau it is necessary to perform an antigen retrieval. However, in the case of wasteosomes, an excessive antigen retrieval with boiling dissolves their polyglucosan structure, releases the entrapped proteins and, thus, prevents their detection. After performing an adequate pre-treatment, with an intermediate time of boiling, we observed that some brain wasteosomes from patients with Alzheimer’s disease (AD) contained tau, while we did not detect tau protein in those from non-AD patients. These observations pointed the different composition of wasteosomes depending on the neuropathological condition and reinforce the role of wasteosomes as waste containers.
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Affiliation(s)
- Marta Riba
- Secció de Fisiologia, Departament de Bioquímica i Fisiologia, Facultat de Farmàcia i Ciències de l’Alimentació, Universitat de Barcelona, Barcelona, Spain
- Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Jaume del Valle
- Secció de Fisiologia, Departament de Bioquímica i Fisiologia, Facultat de Farmàcia i Ciències de l’Alimentació, Universitat de Barcelona, Barcelona, Spain
- Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Clara Romera
- Secció de Fisiologia, Departament de Bioquímica i Fisiologia, Facultat de Farmàcia i Ciències de l’Alimentació, Universitat de Barcelona, Barcelona, Spain
- Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
| | - Raquel Alsina
- Secció de Fisiologia, Departament de Bioquímica i Fisiologia, Facultat de Farmàcia i Ciències de l’Alimentació, Universitat de Barcelona, Barcelona, Spain
- Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
| | - Laura Molina-Porcel
- Alzheimer’s Disease and Other Cognitive Disorders Unit, Neurology Service, Hospital Clinic, Institut d’Investigacions Biomèdiques August Pi i Sunyer, Universitat de Barcelona, Barcelona, Spain
- Neurological Tissue Bank of the Biobanc-Hospital Clinic-IDIBAPS, Barcelona, Spain
| | - Carme Pelegrí
- Secció de Fisiologia, Departament de Bioquímica i Fisiologia, Facultat de Farmàcia i Ciències de l’Alimentació, Universitat de Barcelona, Barcelona, Spain
- Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
- *Correspondence: Carme Pelegrí,
| | - Jordi Vilaplana
- Secció de Fisiologia, Departament de Bioquímica i Fisiologia, Facultat de Farmàcia i Ciències de l’Alimentació, Universitat de Barcelona, Barcelona, Spain
- Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
- Jordi Vilaplana,
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Wasteosomes ( corpora amylacea) as a hallmark of chronic glymphatic insufficiency. Proc Natl Acad Sci U S A 2022; 119:e2211326119. [PMID: 36409907 PMCID: PMC9860256 DOI: 10.1073/pnas.2211326119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In different organs and tissues, the lymphatic system serves as a drainage system for interstitial fluid and is useful for removing substances that would otherwise accumulate in the interstitium. In the brain, which lacks lymphatic circulation, the drainage and cleaning function is performed by the glymphatic system, called so for its dependence on glial cells and its similar function to that of the lymphatic system. In the present article, we define glymphatic insufficiency as the inability of the glymphatic system to properly perform the brain cleaning function. Furthermore, we propose that corpora amylacea or wasteosomes, which are protective structures that act as waste containers and accumulate waste products, are, in fact, a manifestation of chronic glymphatic insufficiency. Assuming this premise, we provide an explanation that coherently links the formation, distribution, structure, and function of these bodies in the human brain. Moreover, we open up new perspectives in the study of the glymphatic system since wasteosomes can provide information about which variables have the greatest impact on the glymphatic system and which diseases occur with chronic glymphatic insufficiency. For example, based on the presence of wasteosomes, it seems that aging, sleep disorders, and cerebrovascular pathologies have the highest impact on the glymphatic system, whereas neurodegenerative diseases have a more limited impact. Furthermore, as glymphatic insufficiency is a risk factor for neurodegenerative diseases, information provided by wasteosomes could help to define the strategies and actions that can prevent glymphatic disruptions, thus limiting the risk of developing neurodegenerative diseases.
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