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Viola G, Trivellato D, Meulli L, Tira R, Lauriola A, Munari F, Montagnana M, Buffelli M, Assfalg M, D'Onofrio M. Stable ubiquitin conjugation for biological interrogation of ubiquitinated tau repeat domain. Bioorg Chem 2024; 150:107549. [PMID: 38896934 DOI: 10.1016/j.bioorg.2024.107549] [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: 04/17/2024] [Revised: 05/29/2024] [Accepted: 06/07/2024] [Indexed: 06/21/2024]
Abstract
Protein semisynthesis approaches are key for gaining insights into the effects of post-translational modifications (PTMs) on the structure and function of modified proteins. Among PTMs, ubiquitination involves the conjugation of a small protein modifier to a substrate amino acid residue and is unique in controlling a variety of cellular processes. Interest has grown in understanding the role of ubiquitination in neurodegenerative conditions, including tauopathies. The latter are characterized by the accumulation of the intrinsically disordered protein tau in the form of neurofibrillary tangles in the brains of patients. The presence of ubiquitinated tau in the pathological aggregates suggests that ubiquitination might play a role in the formation of abnormal protein deposits. In this study, we developed a new strategy, based on dehydroalanine chemistry, to install wild type ubiquitin on a tau repeat domain construct with site-specificity. We optimized a three-step reaction which yielded a good amount of highly pure tau repeat domain ubiquitinated in position 353. The structural features of the conjugate were examined by circular dichroism and NMR spectroscopy. The ubiquitinated tau was challenged in a number of assays: fibrils formation under aggregating conditions in vitro, chemical stability upon exposure to a variety of biological media including cell extracts, and internalization into astrocytes. The results demonstrated the wide applicability of the new semisynthetic strategy for the investigation of ubiquitinated substrates in vitro or in cell, and in particular for studying if ubiquitination has a role in the molecular mechanisms that underlie the aberrant transition of tau into pathological aggregates.
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Affiliation(s)
- Giovanna Viola
- Department of Biotechnology, University of Verona, 37134 Verona, Italy
| | | | - Lorenzo Meulli
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, 37134 Verona, Italy
| | - Roberto Tira
- Department of Biotechnology, University of Verona, 37134 Verona, Italy
| | - Angela Lauriola
- Department of Biotechnology, University of Verona, 37134 Verona, Italy
| | - Francesca Munari
- Department of Biotechnology, University of Verona, 37134 Verona, Italy
| | - Martina Montagnana
- Department of Engineering for Innovation Medicine, University of Verona, 37134 Verona, Italy
| | - Mario Buffelli
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, 37134 Verona, Italy
| | - Michael Assfalg
- Department of Biotechnology, University of Verona, 37134 Verona, Italy
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2
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Chandra S, Vassar R. The role of the gut microbiome in the regulation of astrocytes in Alzheimer's disease. Neurotherapeutics 2024:e00425. [PMID: 39054180 DOI: 10.1016/j.neurot.2024.e00425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Revised: 07/06/2024] [Accepted: 07/11/2024] [Indexed: 07/27/2024] Open
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disorder and is the most common cause of dementia. AD is characterized pathologically by proteinaceous aggregates composed of amyloid beta (Aβ) and tau as well as progressive neurodegeneration. Concurrently with the buildup of protein aggregates, a strong neuroinflammatory response, in the form of reactive astrocytosis and microgliosis, occurs in the AD brain. It has recently been shown that the gut microbiome (GMB), composed of trillions of bacteria in the human intestine, can regulate both reactive astrocytosis and microgliosis in the context of both amyloidosis and tauopathy. Many studies have implicated microglia in these processes. However, growing evidence suggests that interactions between the GMB and astrocytes have a much larger role than previously thought. In this review, we summarize evidence regarding the gut microbiome in the control of reactive astrocytosis in AD.
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Affiliation(s)
- Sidhanth Chandra
- Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA; Medical Scientist Training Program, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA.
| | - Robert Vassar
- Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA.
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3
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Parra Bravo C, Naguib SA, Gan L. Cellular and pathological functions of tau. Nat Rev Mol Cell Biol 2024:10.1038/s41580-024-00753-9. [PMID: 39014245 DOI: 10.1038/s41580-024-00753-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/10/2024] [Indexed: 07/18/2024]
Abstract
Tau protein is involved in various cellular processes, including having a canonical role in binding and stabilization of microtubules in neurons. Tauopathies are neurodegenerative diseases marked by the abnormal accumulation of tau protein aggregates in neurons, as seen, for example, in conditions such as frontotemporal dementia and Alzheimer disease. Mutations in tau coding regions or that disrupt tau mRNA splicing, tau post-translational modifications and cellular stress factors (such as oxidative stress and inflammation) increase the tendency of tau to aggregate and interfere with its clearance. Pathological tau is strongly implicated in the progression of neurodegenerative diseases, and the propagation of tau aggregates is associated with disease severity. Recent technological advancements, including cryo-electron microscopy and disease models derived from human induced pluripotent stem cells, have increased our understanding of tau-related pathology in neurodegenerative conditions. Substantial progress has been made in deciphering tau aggregate structures and the molecular mechanisms that underlie protein aggregation and toxicity. In this Review, we discuss recent insights into the diverse cellular functions of tau and the pathology of tau inclusions and explore the potential for therapeutic interventions.
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Affiliation(s)
- Celeste Parra Bravo
- Helen and Robert Appel Alzheimer's Disease Research Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Neuroscience Graduate Program, Weill Cornell Graduate School of Medical Sciences, New York, NY, USA
| | - Sarah A Naguib
- Helen and Robert Appel Alzheimer's Disease Research Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Li Gan
- Helen and Robert Appel Alzheimer's Disease Research Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA.
- Neuroscience Graduate Program, Weill Cornell Graduate School of Medical Sciences, New York, NY, USA.
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4
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Iyer AK, Vermunt L, Mirfakhar FS, Minaya M, Acquarone M, Koppisetti RK, Renganathan A, You SF, Danhash EP, Verbeck A, Galasso G, Lee SM, Marsh J, Nana AL, Spina S, Seeley WW, Grinberg LT, Temple S, Teunissen CE, Sato C, Karch CM. Cell autonomous microglia defects in a stem cell model of frontotemporal dementia. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.05.15.24307444. [PMID: 38798451 PMCID: PMC11118656 DOI: 10.1101/2024.05.15.24307444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Neuronal dysfunction has been extensively studied as a central feature of neurodegenerative tauopathies. However, across neurodegenerative diseases, there is strong evidence for active involvement of immune cells like microglia in driving disease pathophysiology. Here, we demonstrate that tau mRNA and protein are expressed in microglia in human brains and in human induced pluripotent stem cell (iPSC)-derived microglia like cells (iMGLs). Using iMGLs harboring the MAPT IVS10+16 mutation and isogenic controls, we demonstrate that a tau mutation is sufficient to alter microglial transcriptional states. We discovered that MAPT IVS10+16 microglia exhibit cytoskeletal abnormalities, stalled phagocytosis, disrupted TREM2/TYROBP networks, and altered metabolism. Additionally, we found that secretory factors from MAPT IVS10+16 iMGLs impact neuronal health, reducing synaptic density in neurons. Key features observed in vitro were recapitulated in human brain tissue and cerebrospinal fluid from MAPT mutations carriers. Together, our findings that MAPT IVS10+16 drives cell-intrinsic dysfunction in microglia that impacts neuronal health has major implications for development of therapeutic strategies.
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Affiliation(s)
- Abhirami K. Iyer
- Department of Psychiatry, Washington University in St Louis, St Louis, MO, USA
| | - Lisa Vermunt
- Neurochemistry Laboratory, Department of Laboratory Medicine, Amsterdam Neuroscience, VU University, Amsterdam UMC, The Netherlands
| | | | - Miguel Minaya
- Department of Psychiatry, Washington University in St Louis, St Louis, MO, USA
| | - Mariana Acquarone
- Department of Psychiatry, Washington University in St Louis, St Louis, MO, USA
| | | | - Arun Renganathan
- Department of Psychiatry, Washington University in St Louis, St Louis, MO, USA
| | - Shih-Feng You
- Department of Psychiatry, Washington University in St Louis, St Louis, MO, USA
| | - Emma P. Danhash
- Department of Psychiatry, Washington University in St Louis, St Louis, MO, USA
| | - Anthony Verbeck
- Department of Psychiatry, Washington University in St Louis, St Louis, MO, USA
| | - Grant Galasso
- Department of Psychiatry, Washington University in St Louis, St Louis, MO, USA
| | - Scott M. Lee
- Department of Psychiatry, Washington University in St Louis, St Louis, MO, USA
| | - Jacob Marsh
- Department of Psychiatry, Washington University in St Louis, St Louis, MO, USA
| | - Alissa L. Nana
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Salvatore Spina
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - William W. Seeley
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
- Department of Pathology, University of California, San Francisco, San Francisco, CA, USA
| | - Lea T. Grinberg
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
- Department of Pathology, University of California, San Francisco, San Francisco, CA, USA
- Department of Pathology, University of Sao Paulo
| | | | - Charlotte E. Teunissen
- Neurochemistry Laboratory, Department of Laboratory Medicine, Amsterdam Neuroscience, VU University, Amsterdam UMC, The Netherlands
| | - Chihiro Sato
- Department of Neurology, Washington University in St Louis, St Louis, MO, USA
- The Tracy Family Stable Isotope Labeling Quantitation Center, Washington University in St Louis, St Louis, MO, USA
| | - Celeste M. Karch
- Department of Psychiatry, Washington University in St Louis, St Louis, MO, USA
- Hope Center for Neurological Disorders, Washington University in St Louis, St Louis, MO, USA
- Charles F. and Joanne Knight Alzheimer Disease Research Center, Washington University School of Medicine, St. Louis, MO, USA
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5
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Sidoryk-Węgrzynowicz M, Adamiak K, Strużyńska L. Astrocyte-Neuron Interaction via the Glutamate-Glutamine Cycle and Its Dysfunction in Tau-Dependent Neurodegeneration. Int J Mol Sci 2024; 25:3050. [PMID: 38474295 DOI: 10.3390/ijms25053050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 02/26/2024] [Accepted: 03/01/2024] [Indexed: 03/14/2024] Open
Abstract
Astroglia constitute the largest group of glial cells and are involved in numerous actions that are critical to neuronal development and functioning, such as maintaining the blood-brain barrier, forming synapses, supporting neurons with nutrients and trophic factors, and protecting them from injury. These properties are deeply affected in the course of many neurodegenerative diseases, including tauopathies, often before the onset of the disease. In this respect, the transfer of essential amino acids such as glutamate and glutamine between neurons and astrocytes in the glutamate-glutamine cycle (GGC) is one example. In this review, we focus on the GGC and the disruption of this cycle in tau-dependent neurodegeneration. A profound understanding of the complex functions of the GGC and, in the broader context, searching for dysfunctions in communication pathways between astrocytes and neurons via GGC in health and disease, is of critical significance for the development of novel mechanism-based therapies for neurodegenerative disorders.
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Affiliation(s)
- Marta Sidoryk-Węgrzynowicz
- Laboratory of Pathoneurochemistry, Department of Neurochemistry, Mossakowski Medical Research Institute, Polish Academy of Sciences, 5 Pawińskiego Str., 02-106 Warsaw, Poland
| | - Kamil Adamiak
- Laboratory of Pathoneurochemistry, Department of Neurochemistry, Mossakowski Medical Research Institute, Polish Academy of Sciences, 5 Pawińskiego Str., 02-106 Warsaw, Poland
| | - Lidia Strużyńska
- Laboratory of Pathoneurochemistry, Department of Neurochemistry, Mossakowski Medical Research Institute, Polish Academy of Sciences, 5 Pawińskiego Str., 02-106 Warsaw, Poland
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6
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Beretta C, Svensson E, Dakhel A, Zyśk M, Hanrieder J, Sehlin D, Michno W, Erlandsson A. Amyloid-β deposits in human astrocytes contain truncated and highly resistant proteoforms. Mol Cell Neurosci 2024; 128:103916. [PMID: 38244652 DOI: 10.1016/j.mcn.2024.103916] [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: 10/27/2023] [Revised: 01/08/2024] [Accepted: 01/15/2024] [Indexed: 01/22/2024] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder that develops over decades. Glial cells, including astrocytes are tightly connected to the AD pathogenesis, but their impact on disease progression is still unclear. Our previous data show that astrocytes take up large amounts of aggregated amyloid-beta (Aβ) but are unable to successfully degrade the material, which is instead stored intracellularly. The aim of the present study was to analyze the astrocytic Aβ deposits composition in detail in order to understand their role in AD propagation. For this purpose, human induced pluripotent cell (hiPSC)-derived astrocytes were exposed to sonicated Aβ42 fibrils and magnetic beads. Live cell imaging and immunocytochemistry confirmed that the ingested Aβ aggregates and beads were transported to the same lysosomal compartments in the perinuclear region, which allowed us to successfully isolate the Aβ deposits from the astrocytes. Using a battery of experimental techniques, including mass spectrometry, western blot, ELISA and electron microscopy we demonstrate that human astrocytes truncate and pack the Aβ aggregates in a way that makes them highly resistant. Moreover, the astrocytes release specifically truncated forms of Aβ via different routes and thereby expose neighboring cells to pathogenic proteins. Taken together, our study establishes a role for astrocytes in mediating Aβ pathology, which could be of relevance for identifying novel treatment targets for AD.
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Affiliation(s)
- C Beretta
- Department of Public Health and Caring Sciences, Molecular Geriatrics, Rudbeck Laboratory, Uppsala University, SE-752 37 Uppsala, Sweden.
| | - E Svensson
- Department of Public Health and Caring Sciences, Molecular Geriatrics, Rudbeck Laboratory, Uppsala University, SE-752 37 Uppsala, Sweden; Department of Neuroinflammation, UCL Queen Square Institute of Neurology, 1 Wakefield Street, WC1N 1PJ London, United Kingdom of Great Britain and Northern Ireland.
| | - A Dakhel
- Department of Public Health and Caring Sciences, Molecular Geriatrics, Rudbeck Laboratory, Uppsala University, SE-752 37 Uppsala, Sweden.
| | - M Zyśk
- Department of Public Health and Caring Sciences, Molecular Geriatrics, Rudbeck Laboratory, Uppsala University, SE-752 37 Uppsala, Sweden.
| | - J Hanrieder
- Department of Psychiatry and Neurochemistry, University of Gothenburg, SE-43180 Gothenburg, Sweden.
| | - D Sehlin
- Department of Public Health and Caring Sciences, Molecular Geriatrics, Rudbeck Laboratory, Uppsala University, SE-752 37 Uppsala, Sweden.
| | - W Michno
- Department of Public Health and Caring Sciences, Molecular Geriatrics, Rudbeck Laboratory, Uppsala University, SE-752 37 Uppsala, Sweden; Science for Life Laboratory, Uppsala University, SE-752 37 Uppsala, Sweden.
| | - A Erlandsson
- Department of Public Health and Caring Sciences, Molecular Geriatrics, Rudbeck Laboratory, Uppsala University, SE-752 37 Uppsala, Sweden.
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7
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Elder GA, Gama Sosa MA, De Gasperi R, Perez Garcia G, Perez GM, Abutarboush R, Kawoos U, Zhu CW, Janssen WGM, Stone JR, Hof PR, Cook DG, Ahlers ST. The Neurovascular Unit as a Locus of Injury in Low-Level Blast-Induced Neurotrauma. Int J Mol Sci 2024; 25:1150. [PMID: 38256223 PMCID: PMC10816929 DOI: 10.3390/ijms25021150] [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: 12/12/2023] [Revised: 01/11/2024] [Accepted: 01/11/2024] [Indexed: 01/24/2024] Open
Abstract
Blast-induced neurotrauma has received much attention over the past decade. Vascular injury occurs early following blast exposure. Indeed, in animal models that approximate human mild traumatic brain injury or subclinical blast exposure, vascular pathology can occur in the presence of a normal neuropil, suggesting that the vasculature is particularly vulnerable. Brain endothelial cells and their supporting glial and neuronal elements constitute a neurovascular unit (NVU). Blast injury disrupts gliovascular and neurovascular connections in addition to damaging endothelial cells, basal laminae, smooth muscle cells, and pericytes as well as causing extracellular matrix reorganization. Perivascular pathology becomes associated with phospho-tau accumulation and chronic perivascular inflammation. Disruption of the NVU should impact activity-dependent regulation of cerebral blood flow, blood-brain barrier permeability, and glymphatic flow. Here, we review work in an animal model of low-level blast injury that we have been studying for over a decade. We review work supporting the NVU as a locus of low-level blast injury. We integrate our findings with those from other laboratories studying similar models that collectively suggest that damage to astrocytes and other perivascular cells as well as chronic immune activation play a role in the persistent neurobehavioral changes that follow blast injury.
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Affiliation(s)
- Gregory A. Elder
- Neurology Service, James J. Peters Department of Veterans Affairs Medical Center, 130 West Kingsbridge Road, Bronx, NY 10468, USA
- Department of Neurology, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, NY 10029, USA;
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, NY 10029, USA; (M.A.G.S.); (R.D.G.)
- Mount Sinai Alzheimer’s Disease Research Center and the Ronald M. Loeb Center for Alzheimer’s Disease, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; (C.W.Z.); (P.R.H.)
| | - Miguel A. Gama Sosa
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, NY 10029, USA; (M.A.G.S.); (R.D.G.)
- General Medical Research Service, James J. Peters Department of Veterans Affairs Medical Center, Bronx, NY 10468, USA
| | - Rita De Gasperi
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, NY 10029, USA; (M.A.G.S.); (R.D.G.)
- Research and Development Service, James J. Peters Department of Veterans Affairs Medical Center, 130 West Kingsbridge Road, Bronx, NY 10468, USA;
| | - Georgina Perez Garcia
- Department of Neurology, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, NY 10029, USA;
- Research and Development Service, James J. Peters Department of Veterans Affairs Medical Center, 130 West Kingsbridge Road, Bronx, NY 10468, USA;
| | - Gissel M. Perez
- Research and Development Service, James J. Peters Department of Veterans Affairs Medical Center, 130 West Kingsbridge Road, Bronx, NY 10468, USA;
| | - Rania Abutarboush
- Department of Neurotrauma, Operational and Undersea Medicine Directorate, Naval Medical ResearchCommand, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA; (R.A.); (U.K.); (S.T.A.)
- The Henry M. Jackson Foundation for the Advancement of Military Medicine Inc., Bethesda, MD 20817, USA
| | - Usmah Kawoos
- Department of Neurotrauma, Operational and Undersea Medicine Directorate, Naval Medical ResearchCommand, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA; (R.A.); (U.K.); (S.T.A.)
- The Henry M. Jackson Foundation for the Advancement of Military Medicine Inc., Bethesda, MD 20817, USA
| | - Carolyn W. Zhu
- Mount Sinai Alzheimer’s Disease Research Center and the Ronald M. Loeb Center for Alzheimer’s Disease, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; (C.W.Z.); (P.R.H.)
- Research and Development Service, James J. Peters Department of Veterans Affairs Medical Center, 130 West Kingsbridge Road, Bronx, NY 10468, USA;
- Department of Geriatrics and Palliative Care, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - William G. M. Janssen
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA;
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - James R. Stone
- Department of Radiology and Medical Imaging, University of Virginia, 480 Ray C Hunt Drive, Charlottesville, VA 22903, USA;
| | - Patrick R. Hof
- Mount Sinai Alzheimer’s Disease Research Center and the Ronald M. Loeb Center for Alzheimer’s Disease, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; (C.W.Z.); (P.R.H.)
- Department of Geriatrics and Palliative Care, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA;
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - David G. Cook
- Geriatric Research Education and Clinical Center, VA Puget Sound Health Care System, 1660 S Columbian Way, Seattle, WA 98108, USA;
- Department of Medicine, University of Washington, 1959 NE Pacific St., Seattle, WA 98195, USA
| | - Stephen T. Ahlers
- Department of Neurotrauma, Operational and Undersea Medicine Directorate, Naval Medical ResearchCommand, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA; (R.A.); (U.K.); (S.T.A.)
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8
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Giusti V, Kaur G, Giusto E, Civiero L. Brain clearance of protein aggregates: a close-up on astrocytes. Mol Neurodegener 2024; 19:5. [PMID: 38229094 DOI: 10.1186/s13024-024-00703-1] [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: 07/17/2023] [Accepted: 01/05/2024] [Indexed: 01/18/2024] Open
Abstract
Protein misfolding and accumulation defines a prevailing feature of many neurodegenerative disorders, finally resulting in the formation of toxic intra- and extracellular aggregates. Intracellular aggregates can enter the extracellular space and be subsequently transferred among different cell types, thus spreading between connected brain districts.Although microglia perform a predominant role in the removal of extracellular aggregated proteins, mounting evidence suggests that astrocytes actively contribute to the clearing process. However, the molecular mechanisms used by astrocytes to remove misfolded proteins are still largely unknown.Here we first provide a brief overview of the progressive transition from soluble monomers to insoluble fibrils that characterizes amyloid proteins, referring to α-Synuclein and Tau as archetypical examples. We then highlight the mechanisms at the basis of astrocyte-mediated clearance with a focus on their potential ability to recognize, collect, internalize and digest extracellular protein aggregates. Finally, we explore the potential of targeting astrocyte-mediated clearance as a future therapeutic approach for the treatment of neurodegenerative disorders characterized by protein misfolding and accumulation.
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Affiliation(s)
| | - Gurkirat Kaur
- Department of Biology, University of Padova, Padua, Italy
| | | | - Laura Civiero
- IRCCS San Camillo Hospital, Venice, Italy.
- Department of Biology, University of Padova, Padua, Italy.
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9
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Hu J, Sha W, Yuan S, Wu J, Huang Y. Aggregation, Transmission, and Toxicity of the Microtubule-Associated Protein Tau: A Complex Comprehension. Int J Mol Sci 2023; 24:15023. [PMID: 37834471 PMCID: PMC10573976 DOI: 10.3390/ijms241915023] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 09/12/2023] [Accepted: 09/18/2023] [Indexed: 10/15/2023] Open
Abstract
The microtubule-associated protein tau is an intrinsically disordered protein containing a few short and transient secondary structures. Tau physiologically associates with microtubules (MTs) for its stabilization and detaches from MTs to regulate its dynamics. Under pathological conditions, tau is abnormally modified, detaches from MTs, and forms protein aggregates in neuronal and glial cells. Tau protein aggregates can be found in a number of devastating neurodegenerative diseases known as "tauopathies", such as Alzheimer's disease (AD), frontotemporal dementia (FTD), corticobasal degeneration (CBD), etc. However, it is still unclear how the tau protein is compacted into ordered protein aggregates, and the toxicity of the aggregates is still debated. Fortunately, there has been considerable progress in the study of tau in recent years, particularly in the understanding of the intercellular transmission of pathological tau species, the structure of tau aggregates, and the conformational change events in the tau polymerization process. In this review, we summarize the concepts of tau protein aggregation and discuss the views on tau protein transmission and toxicity.
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Affiliation(s)
- Jiaxin Hu
- Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China; (J.H.); (W.S.); (S.Y.)
| | - Wenchi Sha
- Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China; (J.H.); (W.S.); (S.Y.)
| | - Shuangshuang Yuan
- Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China; (J.H.); (W.S.); (S.Y.)
| | - Jiarui Wu
- Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China; (J.H.); (W.S.); (S.Y.)
- Key Laboratory of Systems Biology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Hangzhou 310024, China
| | - Yunpeng Huang
- Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China; (J.H.); (W.S.); (S.Y.)
- Key Laboratory of Systems Biology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Hangzhou 310024, China
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