1
|
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.
Collapse
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.
| |
Collapse
|
2
|
Zhao R. Exercise mimetics: a novel strategy to combat neuroinflammation and Alzheimer's disease. J Neuroinflammation 2024; 21:40. [PMID: 38308368 PMCID: PMC10837901 DOI: 10.1186/s12974-024-03031-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 01/25/2024] [Indexed: 02/04/2024] Open
Abstract
Neuroinflammation is a pathological hallmark of Alzheimer's disease (AD), characterized by the stimulation of resident immune cells of the brain and the penetration of peripheral immune cells. These inflammatory processes facilitate the deposition of amyloid-beta (Aβ) plaques and the abnormal hyperphosphorylation of tau protein. Managing neuroinflammation to restore immune homeostasis and decrease neuronal damage is a therapeutic approach for AD. One way to achieve this is through exercise, which can improve brain function and protect against neuroinflammation, oxidative stress, and synaptic dysfunction in AD models. The neuroprotective impact of exercise is regulated by various molecular factors that can be activated in the same way as exercise by the administration of their mimetics. Recent evidence has proven some exercise mimetics effective in alleviating neuroinflammation and AD, and, additionally, they are a helpful alternative option for patients who are unable to perform regular physical exercise to manage neurodegenerative disorders. This review focuses on the current state of knowledge on exercise mimetics, including their efficacy, regulatory mechanisms, progress, challenges, limitations, and future guidance for their application in AD therapy.
Collapse
Affiliation(s)
- Renqing Zhao
- College of Physical Education, Yangzhou University, Yangzhou, China.
| |
Collapse
|
3
|
Lopez G, Magaki SD, Williams CK, Paganini-Hill A, Vinters HV. Characterization of cerebellar amyloid-β deposits in Alzheimer disease. J Neuropathol Exp Neurol 2024; 83:72-78. [PMID: 38114098 PMCID: PMC10799296 DOI: 10.1093/jnen/nlad107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2023] Open
Abstract
Cerebellar amyloid-β (Aβ) plaques are a component of the diagnostic criteria used in Thal staging and ABC scoring for Alzheimer disease (AD) neuropathologic change. However, Aβ deposits in this anatomic compartment are unique and under-characterized; and their relationship with other pathological findings are largely undefined. In 73 cases of pure or mixed AD with an A3 score in the ABC criteria, parenchymal (plaques) and vascular (cerebral amyloid angiopathy [CAA]) cerebellar Aβ-42 deposits were characterized with respect to localization, morphology, density, and intensity. Over 85% of cases demonstrated cerebellar Aβ-42 parenchymal staining that correlated with a Braak stage V-VI/B3 score (p < 0.01). Among the 63 with cerebellar Aβ-42 deposits, a diffuse morphology was observed in 75% of cases, compact without a central dense core in 32%, and compact with a central dense core in 16% (all corresponding to plaques evident on hematoxylin and eosin staining). Cases with Purkinje cell (PC) loss showed higher proportions of PC layer Aβ-42 staining than cases without PC loss (88% vs 44%, p = 0.02), suggesting a link between Aβ-42 deposition and PC damage. Among all 73 cases, CAA was observed in the parenchymal vessels of 19% of cases and in leptomeningeal vessels in 44% of cases.
Collapse
Affiliation(s)
- Gianluca Lopez
- Section of Neuropathology, Department of Pathology and Laboratory Medicine, Ronald Reagan UCLA Medical Center and David Geffen School of Medicine, University of California, Los Angeles, California, USA
- Department of Biomedical, Surgical and Dental Sciences, University of Milan, Milan, Italy
- Division of Pathology, Fondazione IRCCS Ca’ Granda—Ospedale Maggiore Policlinico, Milan, Italy
| | - Shino D Magaki
- Section of Neuropathology, Department of Pathology and Laboratory Medicine, Ronald Reagan UCLA Medical Center and David Geffen School of Medicine, University of California, Los Angeles, California, USA
| | - Christopher Kazu Williams
- Section of Neuropathology, Department of Pathology and Laboratory Medicine, Ronald Reagan UCLA Medical Center and David Geffen School of Medicine, University of California, Los Angeles, California, USA
| | - Annlia Paganini-Hill
- Department of Neurology, University of California, Irvine, Irvine, California, USA
| | - Harry V Vinters
- Section of Neuropathology, Department of Pathology and Laboratory Medicine, Ronald Reagan UCLA Medical Center and David Geffen School of Medicine, University of California, Los Angeles, California, USA
- Department of Neurology, Ronald Reagan UCLA Medical Center and David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
| |
Collapse
|
4
|
Huang Y, Zhang W, Guo X, Zhang Y, Wu J, Zu H. Cellular cholesterol loss by DHCR24 knockdown leads to Aβ production by changing APP intracellular localization. J Lipid Res 2023; 64:100367. [PMID: 37011864 PMCID: PMC10173783 DOI: 10.1016/j.jlr.2023.100367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 02/23/2023] [Accepted: 03/16/2023] [Indexed: 04/03/2023] Open
Abstract
For the past 20 years, the majority of cell culture studies reported that increasing cholesterol level increases amyloid-β (Aβ) production. Conversely, other studies and genetic evidences support that cellular cholesterol loss leads to Aβ generation. As a highly controversial issue in Alzheimer's disease (AD) pathogenesis,the apparent contradiction prompted us to again explore the role of cellular cholesterol in Aβ production. Here, we adopted new neuronal and astrocytic cell models induced by 3β-hydroxysterol-Δ24 reductase (DHCR24), which obviously differ from the widely used cell models with overexpressing amyloid precursor protein (APP) in the majority of previous studies. In neuronal and astrocytic cell model, we found that deficiency of cellular cholesterol by DHCR24 knock-down obviously increased intracellular and extracellular Aβ generation. Importantly, in cell models with overexpressing APP, we found that APP overexpression could disrupt cellular cholesterol homeostasis and affect function of cells, coupled with the increase of APP β-cleavage product, 99-residue transmembrane C-terminal domain (C99). Therefore, we suppose the results derived from the APP knock-in models will need to be re-evaluated. One rational explanation for the discrepancy between our outcomes and the previous studies could be attributed to the two different cell models. Mechanistically, we showed that cellular cholesterol loss obviously altered APP intracellular localization by affecting cholesterol-related trafficking protein of APP. Therefore, our outcomes strongly support cellular cholesterol loss by DHCR24 knockdown leads to Aβ production.
Collapse
|
5
|
Konstantinidis E, Dakhel A, Beretta C, Erlandsson A. Long-term effects of amyloid-beta deposits in human iPSC-derived astrocytes. Mol Cell Neurosci 2023; 125:103839. [PMID: 36907531 DOI: 10.1016/j.mcn.2023.103839] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 02/27/2023] [Accepted: 03/04/2023] [Indexed: 03/12/2023] Open
Abstract
Growing evidence indicates that astrocytes are tightly connected to Alzheimer's disease (AD) pathogenesis. However, the way in which astrocytes participate in AD initiation and progression remains to be clarified. Our previous data show that astrocytes engulf large amounts of aggregated amyloid-beta (Aβ) but are unable to successfully degrade the material. In this study, we aimed to evaluate how intracellular Aβ-accumulation affects the astrocytes over time. For this purpose, human induced pluripotent cell (hiPSC)-derived astrocytes were exposed to sonicated Aβ-fibrils and then cultured further for one week or ten weeks in Aβ-free medium. Cells from both time points were analyzed for lysosomal proteins and astrocyte reactivity markers and the media were screened for inflammatory cytokines. In addition, the overall health of cytoplasmic organelles was investigated by immunocytochemistry and electron microscopy. Our data demonstrate that long-term astrocytes retained frequent Aβ-inclusions that were enclosed within LAMP1-positive organelles and sustained markers associated with reactivity. Furthermore, Aβ-accumulation resulted in endoplasmic reticulum and mitochondrial swelling, increased secretion of the cytokine CCL2/MCP-1 and formation of pathological lipid structures. Taken together, our results provide valuable information of how intracellular Aβ-deposits affect astrocytes, and thereby contribute to the understanding of the role of astrocytes in AD progression.
Collapse
Affiliation(s)
- Evangelos Konstantinidis
- Uppsala University, Department of Public Health and Caring Sciences, Molecular Geriatrics, Uppsala, Sweden
| | - Abdulkhalek Dakhel
- Uppsala University, Department of Public Health and Caring Sciences, Molecular Geriatrics, Uppsala, Sweden
| | - Chiara Beretta
- Uppsala University, Department of Public Health and Caring Sciences, Molecular Geriatrics, Uppsala, Sweden
| | - Anna Erlandsson
- Uppsala University, Department of Public Health and Caring Sciences, Molecular Geriatrics, Uppsala, Sweden.
| |
Collapse
|
6
|
Zyśk M, Beretta C, Naia L, Dakhel A, Påvénius L, Brismar H, Lindskog M, Ankarcrona M, Erlandsson A. Amyloid-β accumulation in human astrocytes induces mitochondrial disruption and changed energy metabolism. J Neuroinflammation 2023; 20:43. [PMID: 36803838 PMCID: PMC9940442 DOI: 10.1186/s12974-023-02722-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 02/07/2023] [Indexed: 02/22/2023] Open
Abstract
BACKGROUND Astrocytes play a central role in maintaining brain energy metabolism, but are also tightly connected to the pathogenesis of Alzheimer's disease (AD). Our previous studies demonstrate that inflammatory astrocytes accumulate large amounts of aggregated amyloid-beta (Aβ). However, in which way these Aβ deposits influence their energy production remain unclear. METHODS The aim of the present study was to investigate how Aβ pathology in astrocytes affects their mitochondria functionality and overall energy metabolism. For this purpose, human induced pluripotent cell (hiPSC)-derived astrocytes were exposed to sonicated Aβ42 fibrils for 7 days and analyzed over time using different experimental approaches. RESULTS Our results show that to maintain stable energy production, the astrocytes initially increased their mitochondrial fusion, but eventually the Aβ-mediated stress led to abnormal mitochondrial swelling and excessive fission. Moreover, we detected increased levels of phosphorylated DRP-1 in the Aβ-exposed astrocytes, which co-localized with lipid droplets. Analysis of ATP levels, when blocking certain stages of the energy pathways, indicated a metabolic shift to peroxisomal-based fatty acid β-oxidation and glycolysis. CONCLUSIONS Taken together, our data conclude that Aβ pathology profoundly affects human astrocytes and changes their entire energy metabolism, which could result in disturbed brain homeostasis and aggravated disease progression.
Collapse
Affiliation(s)
- Marlena Zyśk
- grid.8993.b0000 0004 1936 9457Department of Public Health and Caring Sciences, Molecular Geriatrics, Rudbeck Laboratory, Uppsala University, 752 37 Uppsala, Sweden
| | - Chiara Beretta
- grid.8993.b0000 0004 1936 9457Department of Public Health and Caring Sciences, Molecular Geriatrics, Rudbeck Laboratory, Uppsala University, 752 37 Uppsala, Sweden
| | - Luana Naia
- grid.4714.60000 0004 1937 0626Department of Neurobiology, Care Sciences and Society, Division of Neurogeriatrics, BioClinicum, Karolinska Institutet, 171 64 Stockholm, Sweden
| | - Abdulkhalek Dakhel
- grid.8993.b0000 0004 1936 9457Department of Public Health and Caring Sciences, Molecular Geriatrics, Rudbeck Laboratory, Uppsala University, 752 37 Uppsala, Sweden
| | - Linnea Påvénius
- grid.4714.60000 0004 1937 0626Science for Life Laboratory, Department of Women’s and Children’s Health, Karolinska Institutet, 171 65 Stockholm, Sweden
| | - Hjalmar Brismar
- grid.4714.60000 0004 1937 0626Science for Life Laboratory, Department of Women’s and Children’s Health, Karolinska Institutet, 171 65 Stockholm, Sweden ,grid.5037.10000000121581746Science for Life Laboratory, Department of Applied Physics, Royal Institute of Technology, Solna, 171 65 Stockholm, Sweden
| | - Maria Lindskog
- grid.8993.b0000 0004 1936 9457Department of Medical Cell Biology, BMC, Uppsala University, 751 23 Uppsala, Sweden
| | - Maria Ankarcrona
- grid.4714.60000 0004 1937 0626Department of Neurobiology, Care Sciences and Society, Division of Neurogeriatrics, BioClinicum, Karolinska Institutet, 171 64 Stockholm, Sweden
| | - Anna Erlandsson
- Department of Public Health and Caring Sciences, Molecular Geriatrics, Rudbeck Laboratory, Uppsala University, 752 37, Uppsala, Sweden.
| |
Collapse
|
7
|
Kim J, Kim YK. Molecular Imaging of Neuroinflammation in Alzheimer's Disease and Mild Cognitive Impairment. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1411:301-326. [PMID: 36949316 DOI: 10.1007/978-981-19-7376-5_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/24/2023]
Abstract
Alzheimer's disease (AD) is the most prevalent neurocognitive disorder. Due to the ineffectiveness of treatments targeting the amyloid cascade, molecular biomarkers for neuroinflammation are attracting attention with increasing knowledge about the role of neuroinflammation in the pathogenesis of AD. This chapter will explore the results of studies using molecular imaging for diagnosing AD and mild cognitive impairment (MCI). Because it is critical to interpreting the data to understand which substances are targeted in molecular imaging, this chapter will discuss the two most significant targets, microglia and astrocytes, as well as the best-known radioligands for each. Then, neuroimaging results with PET neuroinflammation imaging will be reviewed for AD and MCI. Although a growing body of evidence has suggested that these molecular imaging biomarkers for neuroinflammation may have a role in the diagnosis of AD and MCI, the findings are inconsistent or cross-sectional, which indicates that it is difficult to apply the contents in practice due to the need for additional study. In particular, because the results of multiple interventions targeting neuroinflammation were inconclusive, molecular imaging markers for neuroinflammation can be used in combination with conventional markers to select appropriate patients for early intervention for neuroinflammation rather than as a single marker.
Collapse
Affiliation(s)
- Junhyung Kim
- Department of Psychiatry, Korea University College of Medicine, Korea University Guro Hospital, Seoul, Republic of Korea
- Department of Psychiatry, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Yong-Ku Kim
- Department of Psychiatry, Korea University Ansan Hospital, Ansan, Republic of Korea.
| |
Collapse
|
8
|
Delport A, Hewer R. The amyloid precursor protein: a converging point in Alzheimer's disease. Mol Neurobiol 2022; 59:4501-4516. [PMID: 35579846 DOI: 10.1007/s12035-022-02863-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Accepted: 04/30/2022] [Indexed: 11/30/2022]
Abstract
The decades of evidence that showcase the role of amyloid precursor protein (APP), and its fragment amyloidβ (Aβ), in Alzheimer's disease (AD) pathogenesis are irrefutable. However, the absolute focus on the single APP metabolite Aβ as the cause for AD has resulted in APP and its other fragments that possess toxic propensity, to be overlooked as targets for treatment. The complexity of its processing and its association with systematic metabolism suggests that, if misregulated, APP has the potential to provoke an array of metabolic dysfunctions. This review discusses APP and several of its cleaved products with a particular focus on their toxicity and ability to disrupt healthy cellular function, in relation to AD development. We subsequently argue that the reduction of APP, which would result in a concurrent decrease in Aβ as well as all other toxic APP metabolites, would alleviate the toxic environment associated with AD and slow disease progression. A discussion of those drug-like compounds already identified to possess this capacity is also included.
Collapse
Affiliation(s)
- Alexandré Delport
- Discipline of Biochemistry, School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, 3201, South Africa.
| | - Raymond Hewer
- Discipline of Biochemistry, School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, 3201, South Africa
| |
Collapse
|
9
|
Alawode DOT, Fox NC, Zetterberg H, Heslegrave AJ. Alzheimer’s Disease Biomarkers Revisited From the Amyloid Cascade Hypothesis Standpoint. Front Neurosci 2022; 16:837390. [PMID: 35573283 PMCID: PMC9091905 DOI: 10.3389/fnins.2022.837390] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 04/04/2022] [Indexed: 11/25/2022] Open
Abstract
Alzheimer’s disease (AD) is the most common neurodegenerative disease worldwide. Amyloid beta (Aβ) is one of the proteins which aggregate in AD, and its key role in the disease pathogenesis is highlighted in the amyloid cascade hypothesis, which states that the deposition of Aβ in the brain parenchyma is a crucial initiating step in the future development of AD. The sensitivity of instruments used to measure proteins in blood and cerebrospinal fluid has significantly improved, such that Aβ can now successfully be measured in plasma. However, due to the peripheral production of Aβ, there is significant overlap between diagnostic groups. The presence of pathological Aβ within the AD brain has several effects on the cells and surrounding tissue. Therefore, there is a possibility that using markers of tissue responses to Aβ may reveal more information about Aβ pathology and pathogenesis than looking at plasma Aβ alone. In this manuscript, using the amyloid cascade hypothesis as a starting point, we will delve into how the effect of Aβ on the surrounding tissue can be monitored using biomarkers. In particular, we will consider whether glial fibrillary acidic protein, triggering receptor expressed on myeloid cells 2, phosphorylated tau, and neurofilament light chain could be used to phenotype and quantify the tissue response against Aβ pathology in AD.
Collapse
Affiliation(s)
- Deborah O. T. Alawode
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, United Kingdom
- UK Dementia Research Institute at UCL, London, United Kingdom
- *Correspondence: Deborah O. T. Alawode,
| | - Nick C. Fox
- UK Dementia Research Institute at UCL, London, United Kingdom
- Department of Neurodegenerative Disease, Dementia Research Centre, UCL Queen Square Institute of Neurology, London, United Kingdom
| | - Henrik Zetterberg
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, United Kingdom
- UK Dementia Research Institute at UCL, London, United Kingdom
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
| | - Amanda J. Heslegrave
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, United Kingdom
- UK Dementia Research Institute at UCL, London, United Kingdom
- Amanda J. Heslegrave,
| |
Collapse
|
10
|
Van Bulck M, Brandt N, Claus RA, Gräler M, Bräuer AU. Aβ-Induced Alterations in Membrane Lipids Occur before Synaptic Loss Appears. Int J Mol Sci 2022; 23:ijms23042300. [PMID: 35216416 PMCID: PMC8877175 DOI: 10.3390/ijms23042300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 02/16/2022] [Accepted: 02/17/2022] [Indexed: 02/01/2023] Open
Abstract
Loss of active synapses and alterations in membrane lipids are crucial events in physiological aging as well as in neurodegenerative disorders. Both are related to the abnormal aggregation of amyloid-beta (Aβ) species, generally known as amyloidosis. There are two major known human Aβ species: Aβ(1–40) and Aβ(1–42). However, which of these species have more influence on active synapses and membrane lipids is still poorly understood. Additionally, the time-dependent effect of Aβ species on alterations in membrane lipids of hippocampal neurones and glial cells remains unknown. Therefore, our study contributes to a better understanding of the role of Aβ species in the loss of active synapses and the dysregulation of membrane lipids in vitro. We showed that Aβ(1–40) or Aβ(1–42) treatment influences membrane lipids before synaptic loss appears and that the loss of active synapses is not dependent on the Aβ species. Our lipidomic data analysis showed early changes in specific lipid classes such as sphingolipid and glycerophospholipid neurones. Our results underscore the potential role of lipids as a possible early diagnostic biomarker in amyloidosis-related disorders.
Collapse
Affiliation(s)
- Michiel Van Bulck
- Research Group Anatomy, School for Medicine and Health Science, Carl von Ossietzky University Oldenburg, 26129 Oldenburg, Germany;
- Department of Experimental Models of Human Disease, Networked Center of Biomedical Research on Neurodegenerative Diseases (CIBERNED), Institute for Biomedical Research A. Sols (CSIC-UAM), 28029 Madrid, Spain
- Correspondence: (M.V.B.); (A.U.B.)
| | - Nicola Brandt
- Research Group Anatomy, School for Medicine and Health Science, Carl von Ossietzky University Oldenburg, 26129 Oldenburg, Germany;
| | - Ralf A. Claus
- Department of Anaesthesiology and Intensive Care Medicine Center for Molecular Biomedicine(CMB), Jena University Hospital, 07745 Jena, Germany; (R.A.C.); (M.G.)
| | - Markus Gräler
- Department of Anaesthesiology and Intensive Care Medicine Center for Molecular Biomedicine(CMB), Jena University Hospital, 07745 Jena, Germany; (R.A.C.); (M.G.)
- Centre for Sepsis Control and Care (CSCC), Jena University Hospital, 07745 Jena, Germany
| | - Anja U. Bräuer
- Research Group Anatomy, School for Medicine and Health Science, Carl von Ossietzky University Oldenburg, 26129 Oldenburg, Germany;
- Research Centre for Neurosensory Science, Carl von Ossietzky University Oldenburg, 26129 Oldenburg, Germany
- Correspondence: (M.V.B.); (A.U.B.)
| |
Collapse
|
11
|
Britz J, Ojo E, Dhukhwa A, Saito T, Saido TC, Hascup ER, Hascup KN, Tischkau SA. Assessing Sex-Specific Circadian, Metabolic, and Cognitive Phenotypes in the AβPP/PS1 and APPNL-F/NL-F Models of Alzheimer's Disease. J Alzheimers Dis 2022; 85:1077-1093. [PMID: 34897085 PMCID: PMC8900657 DOI: 10.3233/jad-210629] [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] [Indexed: 01/03/2023]
Abstract
BACKGROUND Circadian disruption has long been recognized as a symptom of Alzheimer's disease (AD); however, emerging data suggests that circadian dysfunction occurs early on in disease development, potentially preceding any noticeable cognitive deficits. OBJECTIVE This study compares the onset of AD in male and female wild type (C57BL6/J), transgenic (AβPP/PS1), and knock-in (APPNL-F/NL-F) AD mouse models from the period of plaque initiation (6 months) through 12 months. METHODS Rhythmic daily activity patterns, glucose sensitivity, cognitive function (Morris water maze, MWM), and AD pathology (plaques formation) were assessed. A comparison was made across sexes. RESULTS Sex-dependent hyperactivity in AβPP/PS1 mice was observed. In comparison to C57BL/6J animals, 6-month-old male AβPP/PS1 demonstrated nighttime hyperactivity, as did 12-month-old females. Female AβPP/PS1 animals performed significantly worse on a MWM task than AβPP/PS1 males at 12 months and trended toward increased plaque pathology. APPNL-F/NL-F 12-month-old males performed significantly worse on the MWM task compared to 12-month-old females. Significantly greater plaque pathology occurred in AβPP/PS1 animals as compared to APPNL-F/NL-F animals. Female AβPP/PS1 animals performed significantly worse than APPNL-F/NL-F animals in spatial learning and memory tasks, though this was reversed in males. CONCLUSION Taken together, this study provides novel insights into baseline sex differences, as well as characterizes baseline diurnal activity variations, in the AβPP/PS1 and APPNL-F/NL-F AD mouse models.
Collapse
Affiliation(s)
- Jesse Britz
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL, USA
| | - Emmanuel Ojo
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL, USA
| | - Asmita Dhukhwa
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL, USA
| | - Takashi Saito
- Department of Neurocognitive Science, Institute of Brain Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan
| | - Takaomi C. Saido
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, Wako, Saitama, Japan
| | - Erin R. Hascup
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL, USA,Department of Neurology, Dale and Deborah Smith Center for Alzheimer’s Research and Treatment, Southern Illinois University School of Medicine, Springfield, IL, USA
| | - Kevin N. Hascup
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL, USA,Department of Neurology, Dale and Deborah Smith Center for Alzheimer’s Research and Treatment, Southern Illinois University School of Medicine, Springfield, IL, USA,Department of Medical Microbiology, Immunology and Cell Biology, Southern Illinois University School of Medicine, Springfield, IL, USA
| | - Shelley A. Tischkau
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL, USA,Department of Medical Microbiology, Immunology and Cell Biology, Southern Illinois University School of Medicine, Springfield, IL, USA,Correspondence to: Shelley A. Tischkau, PhD, 801 N. Rutledge, Room 3289, Springfield, IL 62794-9629, USA. Tel.: +1 217 840 6724;
| |
Collapse
|
12
|
Parhizkar S, Holtzman DM. APOE mediated neuroinflammation and neurodegeneration in Alzheimer's disease. Semin Immunol 2022; 59:101594. [PMID: 35232622 PMCID: PMC9411266 DOI: 10.1016/j.smim.2022.101594] [Citation(s) in RCA: 62] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 01/14/2022] [Indexed: 01/15/2023]
Abstract
Neuroinflammation is a central mechanism involved in neurodegeneration as observed in Alzheimer's disease (AD), the most prevalent form of neurodegenerative disease. Apolipoprotein E4 (APOE4), the strongest genetic risk factor for AD, directly influences disease onset and progression by interacting with the major pathological hallmarks of AD including amyloid-β plaques, neurofibrillary tau tangles, as well as neuroinflammation. Microglia and astrocytes, the two major immune cells in the brain, exist in an immune-vigilant state providing immunological defense as well as housekeeping functions that promote neuronal well-being. It is becoming increasingly evident that under disease conditions, these immune cells become progressively dysfunctional in regulating metabolic and immunoregulatory pathways, thereby promoting chronic inflammation-induced neurodegeneration. Here, we review and discuss how APOE and specifically APOE4 directly influences amyloid-β and tau pathology, and disrupts microglial as well as astroglial immunomodulating functions leading to chronic inflammation that contributes to neurodegeneration in AD.
Collapse
Affiliation(s)
- Samira Parhizkar
- Department of Neurology, Hope Center for Neurological Disorders, Knight Alzheimer Disease, Research Center, Washington University, St. Louis, MO 63110, USA
| | - David M. Holtzman
- Department of Neurology, Hope Center for Neurological Disorders, Knight Alzheimer Disease, Research Center, Washington University, St. Louis, MO 63110, USA
| |
Collapse
|
13
|
Complement System in Alzheimer's Disease. Int J Mol Sci 2021; 22:ijms222413647. [PMID: 34948444 PMCID: PMC8705098 DOI: 10.3390/ijms222413647] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Revised: 12/10/2021] [Accepted: 12/15/2021] [Indexed: 01/02/2023] Open
Abstract
Alzheimer’s disease is a type of dementia characterized by problems with short-term memory, cognition, and difficulties with activities of daily living. It is a progressive, neurodegenerative disorder. The complement system is an ancient part of the innate immune system and comprises of more than thirty serum and membrane-bound proteins. This system has three different activating pathways and culminates into the formation of a membrane attack complex that ultimately causes target cell lysis (usually pathogens) The complement system is involved in several important functions in the central nervous system (CNS) that include neurogenesis, synaptic pruning, apoptosis, and neuronal plasticity. Here, we discuss how the complement system is involved in the effective functioning of CNS, while also contributing to chronic neuroinflammation leading to neurodegenerative disorders such as Alzheimer’s disease. We also discuss potential targets in the complement system for stopping its harmful effects via neuroinflammation and provide perspective for the direction of future research in this field.
Collapse
|
14
|
Wu Q, Cortez L, Kamali-Jamil R, Sim V, Wille H, Kar S. Implications of exosomes derived from cholesterol-accumulated astrocytes in Alzheimer's disease pathology. Dis Model Mech 2021; 14:dmm048929. [PMID: 34524402 PMCID: PMC8560497 DOI: 10.1242/dmm.048929] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 09/06/2021] [Indexed: 12/25/2022] Open
Abstract
Amyloid β (Aβ) peptides generated from the amyloid precursor protein (APP) play a critical role in the development of Alzheimer's disease (AD) pathology. Aβ-containing neuronal exosomes, which represent a novel form of intercellular communication, have been shown to influence the function/vulnerability of neurons in AD. Unlike neurons, the significance of exosomes derived from astrocytes remains unclear. In this study, we evaluated the significance of exosomes derived from U18666A-induced cholesterol-accumulated astrocytes in the development of AD pathology. Our results show that cholesterol accumulation decreases exosome secretion, whereas lowering cholesterol increases exosome secretion, from cultured astrocytes. Interestingly, exosomes secreted from U18666A-treated astrocytes contain higher levels of APP, APP-C-terminal fragments, soluble APP, APP secretases and Aβ1-40 than exosomes secreted from control astrocytes. Furthermore, we show that exosomes derived from U18666A-treated astrocytes can lead to neurodegeneration, which is attenuated by decreasing Aβ production or by neutralizing exosomal Aβ peptide with an anti-Aβ antibody. These results, taken together, suggest that exosomes derived from cholesterol-accumulated astrocytes can play an important role in trafficking APP/Aβ peptides and influencing neuronal viability in the affected regions of the AD brain.
Collapse
Affiliation(s)
- Qi Wu
- Department of Medicine (Neurology), University of Alberta, Edmonton, AB T6G 2G3, Canada
| | - Leonardo Cortez
- Department of Medicine (Neurology), University of Alberta, Edmonton, AB T6G 2G3, Canada
| | - Razieh Kamali-Jamil
- Department of Biochemistry, Center for Prions and Protein Folding Diseases, University of Alberta, Edmonton, AB T6G 2G3, Canada
| | - Valerie Sim
- Department of Medicine (Neurology), University of Alberta, Edmonton, AB T6G 2G3, Canada
| | - Holger Wille
- Department of Biochemistry, Center for Prions and Protein Folding Diseases, University of Alberta, Edmonton, AB T6G 2G3, Canada
| | - Satyabrata Kar
- Department of Medicine (Neurology), University of Alberta, Edmonton, AB T6G 2G3, Canada
- Department of Biochemistry, Center for Prions and Protein Folding Diseases, University of Alberta, Edmonton, AB T6G 2G3, Canada
| |
Collapse
|
15
|
Preman P, TCW J, Calafate S, Snellinx A, Alfonso-Triguero M, Corthout N, Munck S, Thal DR, Goate AM, De Strooper B, Arranz AM. Human iPSC-derived astrocytes transplanted into the mouse brain undergo morphological changes in response to amyloid-β plaques. Mol Neurodegener 2021; 16:68. [PMID: 34563212 PMCID: PMC8467145 DOI: 10.1186/s13024-021-00487-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 08/21/2021] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Increasing evidence for a direct contribution of astrocytes to neuroinflammatory and neurodegenerative processes causing Alzheimer's disease comes from molecular and functional studies in rodent models. However, these models may not fully recapitulate human disease as human and rodent astrocytes differ considerably in morphology, functionality, and gene expression. RESULTS To address these challenges, we established an approach to study human astrocytes within the mouse brain by transplanting human induced pluripotent stem cell (hiPSC)-derived astrocyte progenitors into neonatal brains. Xenografted hiPSC-derived astrocyte progenitors differentiated into astrocytes that integrated functionally within the mouse host brain and matured in a cell-autonomous way retaining human-specific morphologies, unique features, and physiological properties. In Alzheimer´s chimeric brains, transplanted hiPSC-derived astrocytes responded to the presence of amyloid plaques undergoing morphological changes that seemed independent of the APOE allelic background. CONCLUSIONS In sum, we describe here a promising approach that consist of transplanting patient-derived and genetically modified astrocytes into the mouse brain to study human astrocyte pathophysiology in the context of Alzheimer´s disease.
Collapse
Affiliation(s)
- Pranav Preman
- grid.511015.1VIB Center for Brain & Disease Research, Leuven, Belgium ,grid.5596.f0000 0001 0668 7884Laboratory for the Research of Neurodegenerative Diseases, Department of Neurosciences, Leuven Brain Institute (LBI), KU Leuven (University of Leuven), Leuven, Belgium
| | - Julia TCW
- grid.59734.3c0000 0001 0670 2351Department of Genetics and Genomic Sciences, Icahn Institute of Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY USA ,grid.59734.3c0000 0001 0670 2351Department of Neuroscience & Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY USA ,grid.59734.3c0000 0001 0670 2351Ronald M. Loeb Center for Alzheimer’s disease, Icahn School of Medicine at Mount Sinai, New York, NY USA
| | - Sara Calafate
- grid.511015.1VIB Center for Brain & Disease Research, Leuven, Belgium ,grid.5596.f0000 0001 0668 7884Laboratory for the Research of Neurodegenerative Diseases, Department of Neurosciences, Leuven Brain Institute (LBI), KU Leuven (University of Leuven), Leuven, Belgium
| | - An Snellinx
- grid.511015.1VIB Center for Brain & Disease Research, Leuven, Belgium ,grid.5596.f0000 0001 0668 7884Laboratory for the Research of Neurodegenerative Diseases, Department of Neurosciences, Leuven Brain Institute (LBI), KU Leuven (University of Leuven), Leuven, Belgium
| | - Maria Alfonso-Triguero
- grid.427629.cAchucarro Basque Center for Neuroscience, Leioa, Spain ,grid.11480.3c0000000121671098Department of Neurosciences, Universidad del País Vasco (UPV/EHU), Leioa, Spain
| | - Nikky Corthout
- grid.511015.1VIB Center for Brain & Disease Research, Leuven, Belgium ,grid.5596.f0000 0001 0668 7884Laboratory for the Research of Neurodegenerative Diseases, Department of Neurosciences, Leuven Brain Institute (LBI), KU Leuven (University of Leuven), Leuven, Belgium ,VIB Bio Imaging Core, Campus Gasthuisberg, 3000 Leuven, Belgium
| | - Sebastian Munck
- grid.511015.1VIB Center for Brain & Disease Research, Leuven, Belgium ,grid.5596.f0000 0001 0668 7884Laboratory for the Research of Neurodegenerative Diseases, Department of Neurosciences, Leuven Brain Institute (LBI), KU Leuven (University of Leuven), Leuven, Belgium ,VIB Bio Imaging Core, Campus Gasthuisberg, 3000 Leuven, Belgium
| | - Dietmar Rudolf Thal
- grid.5596.f0000 0001 0668 7884Laboratory for Neuropathology, Department of Imaging and Pathology, Leuven Brain Institute (LBI), Department of Pathology, KU Leuven (University of Leuven), University Hospital Leuven, Leuven, Belgium
| | - Alison M Goate
- grid.59734.3c0000 0001 0670 2351Department of Genetics and Genomic Sciences, Icahn Institute of Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY USA ,grid.59734.3c0000 0001 0670 2351Department of Neuroscience & Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY USA ,grid.59734.3c0000 0001 0670 2351Ronald M. Loeb Center for Alzheimer’s disease, Icahn School of Medicine at Mount Sinai, New York, NY USA
| | - Bart De Strooper
- grid.511015.1VIB Center for Brain & Disease Research, Leuven, Belgium ,grid.5596.f0000 0001 0668 7884Laboratory for the Research of Neurodegenerative Diseases, Department of Neurosciences, Leuven Brain Institute (LBI), KU Leuven (University of Leuven), Leuven, Belgium ,grid.83440.3b0000000121901201Dementia Research Institute, University College London, London, UK
| | - Amaia M Arranz
- grid.511015.1VIB Center for Brain & Disease Research, Leuven, Belgium ,grid.5596.f0000 0001 0668 7884Laboratory for the Research of Neurodegenerative Diseases, Department of Neurosciences, Leuven Brain Institute (LBI), KU Leuven (University of Leuven), Leuven, Belgium ,grid.427629.cAchucarro Basque Center for Neuroscience, Leioa, Spain ,grid.424810.b0000 0004 0467 2314Ikerbasque Basque Foundation for Science, Bilbao, Spain
| |
Collapse
|
16
|
Viejo L, Noori A, Merrill E, Das S, Hyman BT, Serrano-Pozo A. Systematic review of human post-mortem immunohistochemical studies and bioinformatics analyses unveil the complexity of astrocyte reaction in Alzheimer's disease. Neuropathol Appl Neurobiol 2021; 48:e12753. [PMID: 34297416 PMCID: PMC8766893 DOI: 10.1111/nan.12753] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 06/29/2021] [Accepted: 07/12/2021] [Indexed: 12/24/2022]
Abstract
AIMS Reactive astrocytes in Alzheimer's disease (AD) have traditionally been demonstrated by increased glial fibrillary acidic protein (GFAP) immunoreactivity; however, astrocyte reaction is a complex and heterogeneous phenomenon involving multiple astrocyte functions beyond cytoskeletal remodelling. To better understand astrocyte reaction in AD, we conducted a systematic review of astrocyte immunohistochemical studies in post-mortem AD brains followed by bioinformatics analyses on the extracted reactive astrocyte markers. METHODS NCBI PubMed, APA PsycInfo and WoS-SCIE databases were interrogated for original English research articles with the search terms 'Alzheimer's disease' AND 'astrocytes.' Bioinformatics analyses included protein-protein interaction network analysis, pathway enrichment, and transcription factor enrichment, as well as comparison with public human -omics datasets. RESULTS A total of 306 articles meeting eligibility criteria rendered 196 proteins, most of which were reported to be upregulated in AD vs control brains. Besides cytoskeletal remodelling (e.g., GFAP), bioinformatics analyses revealed a wide range of functional alterations including neuroinflammation (e.g., IL6, MAPK1/3/8 and TNF), oxidative stress and antioxidant defence (e.g., MT1A/2A, NFE2L2, NOS1/2/3, PRDX6 and SOD1/2), lipid metabolism (e.g., APOE, CLU and LRP1), proteostasis (e.g., cathepsins, CRYAB and HSPB1/2/6/8), extracellular matrix organisation (e.g., CD44, MMP1/3 and SERPINA3), and neurotransmission (e.g., CHRNA7, GABA, GLUL, GRM5, MAOB and SLC1A2), among others. CTCF and ESR1 emerged as potential transcription factors driving these changes. Comparison with published -omics datasets validated our results, demonstrating a significant overlap with reported transcriptomic and proteomic changes in AD brains and/or CSF. CONCLUSIONS Our systematic review of the neuropathological literature reveals the complexity of AD reactive astrogliosis. We have shared these findings as an online resource available at www.astrocyteatlas.org.
Collapse
Affiliation(s)
- Lucía Viejo
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA.,MassGeneral Institute for Neurodegenerative Disease (MIND), Charlestown, MA, USA.,Departamento de Farmacología y Terapéutica, Universidad Autónoma de Madrid, Madrid, Spain
| | - Ayush Noori
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA.,MassGeneral Institute for Neurodegenerative Disease (MIND), Charlestown, MA, USA.,Harvard College, Cambridge, MA, USA.,MIND Data Science Lab, Cambridge, MA, USA.,Massachusetts Alzheimer's Disease Research Center, Charlestown, MA, USA
| | - Emily Merrill
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA.,MassGeneral Institute for Neurodegenerative Disease (MIND), Charlestown, MA, USA.,MIND Data Science Lab, Cambridge, MA, USA
| | - Sudeshna Das
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA.,MassGeneral Institute for Neurodegenerative Disease (MIND), Charlestown, MA, USA.,MIND Data Science Lab, Cambridge, MA, USA.,Massachusetts Alzheimer's Disease Research Center, Charlestown, MA, USA.,Harvard Medical School, Harvard University, Boston, MA, USA
| | - Bradley T Hyman
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA.,MassGeneral Institute for Neurodegenerative Disease (MIND), Charlestown, MA, USA.,Massachusetts Alzheimer's Disease Research Center, Charlestown, MA, USA.,Harvard Medical School, Harvard University, Boston, MA, USA
| | - Alberto Serrano-Pozo
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA.,MassGeneral Institute for Neurodegenerative Disease (MIND), Charlestown, MA, USA.,Massachusetts Alzheimer's Disease Research Center, Charlestown, MA, USA.,Harvard Medical School, Harvard University, Boston, MA, USA
| |
Collapse
|
17
|
Wang J, Ding Y, Zhuang L, Wang Z, Xiao W, Zhu J. Ginkgolide B‑induced AMPK pathway activation protects astrocytes by regulating endoplasmic reticulum stress, oxidative stress and energy metabolism induced by Aβ1‑42. Mol Med Rep 2021; 23:457. [PMID: 33880582 PMCID: PMC8072312 DOI: 10.3892/mmr.2021.12096] [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: 07/20/2020] [Accepted: 01/11/2021] [Indexed: 02/06/2023] Open
Abstract
Ginkgolide B (GB), the diterpenoid lactone compound isolated from the extracts of Ginkgo biloba leaves, significantly improves cognitive impairment, but its potential pharmacological effect on astrocytes induced by β-amyloid (Aβ)1-42 remains to be elucidated. The present study aimed to investigate the protective effect and mechanism of GB on astrocytes with Aβ1-42-induced apoptosis in Alzheimer's disease (AD). Astrocytes obtained from Sprague Dawley rats were randomly divided into control, Aβ, GB and GB + compound C groups. Cell viability and apoptosis were analyzed using Cell Counting Kit-8 and flow cytometry assays, respectively. Protein and mRNA expression levels were analyzed using western blotting and reverse transcription-quantitative PCR, respectively. The levels of superoxide dismutase (SOD), malondialdehyde (MDA), glutathione peroxidase (GSH-Px), reactive oxygen species (ROS) and ATP were determined using the corresponding commercial kits. The findings revealed that GB attenuated Aβ1-42-induced apoptosis and the 5′ adenosine monophosphate- activated protein kinase (AMPK) inhibitor compound C reversed the protective effects of GB. In addition, GB reversed Aβ1-42-induced oxidative damage and energy metabolism disorders, including decreases in the levels of SOD, GSH-Px and ATP and increased the levels of MDA and ROS in astrocytes, while compound C reversed the anti-oxidative effect and the involvement of GB in maintaining energy metabolism in astrocytes. Finally, GB decreased the expression levels of the endoplasmic reticulum stress (ERS) proteins and the apoptotic protein CHOP and increased both mRNA and protein expression of the components of the energy metabolism-related AMPK/peroxisome proliferator-activated receptor γ coactivator 1α/peroxisome proliferator-activated receptor α and anti-oxidation-related nuclear respiratory factor 2/heme oxygenase 1/NAD(P)H dehydrogenase (quinone 1) pathways and downregulated the expression of β-secretase 1. However, compound C could antagonize these effects. In conclusion, the findings demonstrated that GB protected against Aβ1-42-induced apoptosis by inhibiting ERS, oxidative stress, energy metabolism disorders and Aβ1-42 production probably by activating AMPK signaling pathways. The findings provided an innovative insight into the treatment using GB as a therapeutic in Aβ1-42-related AD.
Collapse
Affiliation(s)
- Jing Wang
- School of Food Science and Technology, Dalian Polytechnic University, Dalian, Liaoning 116034, P.R. China
| | - Yan Ding
- School of Food Science and Technology, Dalian Polytechnic University, Dalian, Liaoning 116034, P.R. China
| | - Linwu Zhuang
- School of Food Science and Technology, Dalian Polytechnic University, Dalian, Liaoning 116034, P.R. China
| | - Zhenzhong Wang
- Jiangsu Kanion Pharmaceutical Co. Ltd., Lianyungang, Jiangsu 222000, P.R. China
| | - Wei Xiao
- Jiangsu Kanion Pharmaceutical Co. Ltd., Lianyungang, Jiangsu 222000, P.R. China
| | - Jingbo Zhu
- School of Food Science and Technology, Dalian Polytechnic University, Dalian, Liaoning 116034, P.R. China
| |
Collapse
|
18
|
Leng F, Edison P. Neuroinflammation and microglial activation in Alzheimer disease: where do we go from here? Nat Rev Neurol 2021; 17:157-172. [PMID: 33318676 DOI: 10.1038/s41582-020-00435-y] [Citation(s) in RCA: 1203] [Impact Index Per Article: 401.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/11/2020] [Indexed: 12/17/2022]
Abstract
Alzheimer disease (AD) is the most common form of neurodegenerative disease, estimated to contribute 60-70% of all cases of dementia worldwide. According to the prevailing amyloid cascade hypothesis, amyloid-β (Aβ) deposition in the brain is the initiating event in AD, although evidence is accumulating that this hypothesis is insufficient to explain many aspects of AD pathogenesis. The discovery of increased levels of inflammatory markers in patients with AD and the identification of AD risk genes associated with innate immune functions suggest that neuroinflammation has a prominent role in the pathogenesis of AD. In this Review, we discuss the interrelationships between neuroinflammation and amyloid and tau pathologies as well as the effect of neuroinflammation on the disease trajectory in AD. We specifically focus on microglia as major players in neuroinflammation and discuss the spatial and temporal variations in microglial phenotypes that are observed under different conditions. We also consider how these cells could be modulated as a therapeutic strategy for AD.
Collapse
Affiliation(s)
- Fangda Leng
- Department of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, London, UK
| | - Paul Edison
- Department of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, London, UK.
| |
Collapse
|
19
|
Acioglu C, Li L, Elkabes S. Contribution of astrocytes to neuropathology of neurodegenerative diseases. Brain Res 2021; 1758:147291. [PMID: 33516810 DOI: 10.1016/j.brainres.2021.147291] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 12/10/2020] [Accepted: 01/05/2021] [Indexed: 02/08/2023]
Abstract
Classically, the loss of vulnerable neuronal populations in neurodegenerative diseases was considered to be the consequence of cell autonomous degeneration of neurons. However, progress in the understanding of glial function, the availability of improved animal models recapitulating the features of the human diseases, and the development of new approaches to derive glia and neurons from induced pluripotent stem cells obtained from patients, provided novel information that altered this view. Current evidence strongly supports the notion that non-cell autonomous mechanisms contribute to the demise of neurons in neurodegenerative disorders, and glia causally participate in the pathogenesis and progression of these diseases. In addition to microglia, astrocytes have emerged as key players in neurodegenerative diseases and will be the focus of the present review. Under the influence of pathological stimuli present in the microenvironment of the diseased CNS, astrocytes undergo morphological, transcriptional, and functional changes and become reactive. Reactive astrocytes are heterogeneous and exhibit neurotoxic (A1) or neuroprotective (A2) phenotypes. In recent years, single-cell or single-nucleus transcriptome analyses unraveled new, disease-specific phenotypes beyond A1/A2. These investigations highlighted the complexity of the astrocytic responses to CNS pathology. The present review will discuss the contribution of astrocytes to neurodegenerative diseases with particular emphasis on Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis and frontotemporal dementia. Some of the commonalties and differences in astrocyte-mediated mechanisms that possibly drive the pathogenesis or progression of the diseases will be summarized. The emerging view is that astrocytes are potential new targets for therapeutic interventions. A comprehensive understanding of astrocyte heterogeneity and disease-specific phenotypic complexity could facilitate the design of novel strategies to treat neurodegenerative disorders.
Collapse
Affiliation(s)
- Cigdem Acioglu
- The Reynolds Family Spine Laboratory, Department of Neurological Surgery, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, United States.
| | - Lun Li
- The Reynolds Family Spine Laboratory, Department of Neurological Surgery, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, United States.
| | - Stella Elkabes
- The Reynolds Family Spine Laboratory, Department of Neurological Surgery, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, United States.
| |
Collapse
|
20
|
Sarkar S, Biswas SC. Astrocyte subtype-specific approach to Alzheimer's disease treatment. Neurochem Int 2021; 145:104956. [PMID: 33503465 DOI: 10.1016/j.neuint.2021.104956] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 01/01/2021] [Accepted: 01/05/2021] [Indexed: 01/08/2023]
Abstract
Astrocytes respond to any pathological condition in the central nervous system (CNS) including Alzheimer's disease (AD), and this response is called astrocyte reactivity. Astrocyte reaction to a CNS insult is a highly heterogeneous phenomenon in which the astrocytes undergo a set of morphological, molecular and functional changes with a characteristic secretome profile. Such astrocytes are termed as 'reactive astrocytes'. Controversies regarding the reactive astrocytes abound. Recently, a continuum of reactive astrocyte profiles with distinct transcriptional states has been identified. Among them, disease-associated astrocytes (DAA) were uniquely present in AD mice and expressed a signature set of genes implicated in complement cascade, endocytosis and aging. Earlier, two stimulus-specific reactive astrocyte subtypes with their unique transcriptomic signatures were identified using mouse models of neuroinflammation and ischemia and termed as A1 astrocytes (detrimental) and A2 astrocytes (beneficial) respectively. Interestingly, although most of the A1 signature genes were also detected in DAA, as opposed to A2 astrocyte signatures, some of the A1 specific genes were expressed in other astrocyte subtypes, indicating that these nomenclature-based signatures are not very specific. In this review, we elaborate the disparate functions and cytokine profiles of reactive astrocyte subtypes in AD and tried to distinguish them by designating neurotoxic astrocytes as A1-like and neuroprotective ones as A2-like without directly referring to the A1/A2 original nomenclature. We have also focused on the dual nature from a functional perspective of some cytokines depending on AD-stage, highlighting a number of them as major candidates in AD therapy. Therefore, we suggest that promoting subtype-specific beneficial roles, inhibiting subtype-specific detrimental roles or targeting subtype-specific cytokines constitute a novel therapeutic approach to AD treatment.
Collapse
Affiliation(s)
- Sukanya Sarkar
- Cell Biology and Physiology Division, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata, 700 032, India
| | - Subhas C Biswas
- Cell Biology and Physiology Division, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata, 700 032, India.
| |
Collapse
|
21
|
Kim D, Bae GH, Kim HY, Jeon H, Kim K, Shin J, Lee S, Hong S, Kim I, Kim Y. Orally Administered Benzofuran Derivative Disaggregated Aβ Plaques and Oligomers in the Brain of 5XFAD Alzheimer Transgenic Mouse. ACS Chem Neurosci 2021; 12:99-108. [PMID: 33332107 DOI: 10.1021/acschemneuro.0c00606] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Amyloid-β (Aβ) aggregated forms are highly associated with the onset of Alzheimer's disease (AD). Aβ abnormally accumulates in the brain and induces neuronal damages and symptoms of AD such as cognitive impairment and memory loss. Since an antibody drug, aducanumab, reduces Aβ aggregates and delays clinical decline, clearance of accumulated Aβ in the brain is accounted as a therapeutic approach to treat AD. In this study, we synthesized 17 benzofuran derivatives that may disaggregate Aβ oligomers and plaques into inert monomers. By a series of Aβ aggregation inhibition and aggregates' disaggregation assays utilizing thioflavin T assays and gel electrophoresis, YB-9, 2-((5-methoxy-3-(4-methoxyphenyl)benzofuran-6-yl)oxy)acetic acid, was selected as the final Aβ-disaggregator candidate. When it was orally administered to the 8-month-old male transgenic mouse model with five familial AD mutations (5XFAD) via drinking water daily for two months, Aβ oligomers and plaques in hippocampus were reduced. Consequently, decreased astrogliosis and rescued synaptic dysfunction were observed in the hippocampus of YB-9-treated 5XFAD mice compared with the untreated transgenic control group.
Collapse
Affiliation(s)
- DaWon Kim
- Pharmaceutical Sciences Division and Wisconsin Center for NanoBioSystems, University of Wisconsin, Madison, Wisconsin 53705, United States
| | | | | | | | | | | | | | - Seungpyo Hong
- Pharmaceutical Sciences Division and Wisconsin Center for NanoBioSystems, University of Wisconsin, Madison, Wisconsin 53705, United States
| | | | | |
Collapse
|
22
|
Asken BM, Elahi FM, La Joie R, Strom A, Staffaroni AM, Lindbergh CA, Apple AC, You M, Weiner-Light S, Brathaban N, Fernandes N, Karydas A, Wang P, Rojas JC, Boxer AL, Miller BL, Rabinovici GD, Kramer JH, Casaletto KB. Plasma Glial Fibrillary Acidic Protein Levels Differ Along the Spectra of Amyloid Burden and Clinical Disease Stage. J Alzheimers Dis 2020; 78:265-276. [PMID: 32986672 DOI: 10.3233/jad-200755] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Measuring plasma glial fibrillary acidic protein (GFAP) alongside cortical amyloid-β (Aβ) may shed light on astrocytic changes in aging and Alzheimer's disease (AD). OBJECTIVE To examine associations between plasma GFAP and cortical Aβ deposition in older adults across the typical aging-to-AD dementia spectrum. METHODS We studied two independent samples from UCSF (Cohort 1, N = 50; Cohort 2, N = 37) covering the spectra of clinical severity (CDR Sum of Boxes; CDR-SB) and Aβ-PET burden. Aβ-PET was completed with either florbetapir or Pittsburgh Compound B and standardized uptake value ratios were converted to the Centiloid (CL) scale for analyses. All participants with CDR-SB > 0 were Aβ-PET positive, while clinically normal participants (CDR-SB = 0) were a mix of Aβ-PET positive and negative. Regression analyses evaluated main effect and interaction associations between plasma GFAP, Aβ-PET, and clinical severity. RESULTS In both cohorts, plasma GFAP increased linearly with Aβ-PET CLs in clinically normal older adults. In Cohort 2, which included participants with more severe clinical dysfunction and Aβ-PET burden, the association between Aβ and GFAP became curvilinear (inverted U-shape; quadratic model R2 change = 0.165, p = 0.009), and Aβ-PET interacted with CDR-SB (R2 change = 0.164, p = 0.007): older adults with intermediate functional impairment (CDR-SB = 0.5-4.0) showed a weak (negative) association between Aβ-PET CLs and plasma GFAP, while older adults with dementia (CDR-SB > 4.0) showed a strong, negative association of higher Aβ-PET CLs with lower plasma GFAP. CONCLUSION The relationship between astrocytic integrity and cortical Aβ may be highly dynamic, with linear, positive associations early in disease that diverge in more severe disease stages.
Collapse
Affiliation(s)
- Breton M Asken
- Department of Neurology, Memory and Aging Center, Weill Institute for Neurosciences, University of California at San Francisco (UCSF), San Francisco, CA, USA
| | - Fanny M Elahi
- Department of Neurology, Memory and Aging Center, Weill Institute for Neurosciences, University of California at San Francisco (UCSF), San Francisco, CA, USA
| | - Renaud La Joie
- Department of Neurology, Memory and Aging Center, Weill Institute for Neurosciences, University of California at San Francisco (UCSF), San Francisco, CA, USA
| | - Amelia Strom
- Department of Neurology, Memory and Aging Center, Weill Institute for Neurosciences, University of California at San Francisco (UCSF), San Francisco, CA, USA
| | - Adam M Staffaroni
- Department of Neurology, Memory and Aging Center, Weill Institute for Neurosciences, University of California at San Francisco (UCSF), San Francisco, CA, USA
| | - Cutter A Lindbergh
- Department of Neurology, Memory and Aging Center, Weill Institute for Neurosciences, University of California at San Francisco (UCSF), San Francisco, CA, USA
| | - Alexandra C Apple
- Department of Neurology, Memory and Aging Center, Weill Institute for Neurosciences, University of California at San Francisco (UCSF), San Francisco, CA, USA
| | - Michelle You
- Department of Neurology, Memory and Aging Center, Weill Institute for Neurosciences, University of California at San Francisco (UCSF), San Francisco, CA, USA
| | - Sophia Weiner-Light
- Department of Neurology, Memory and Aging Center, Weill Institute for Neurosciences, University of California at San Francisco (UCSF), San Francisco, CA, USA
| | - Nivetha Brathaban
- Department of Neurology, Memory and Aging Center, Weill Institute for Neurosciences, University of California at San Francisco (UCSF), San Francisco, CA, USA
| | - Nicole Fernandes
- Department of Neurology, Memory and Aging Center, Weill Institute for Neurosciences, University of California at San Francisco (UCSF), San Francisco, CA, USA
| | - Anna Karydas
- Department of Neurology, Memory and Aging Center, Weill Institute for Neurosciences, University of California at San Francisco (UCSF), San Francisco, CA, USA
| | - Paul Wang
- Department of Neurology, Memory and Aging Center, Weill Institute for Neurosciences, University of California at San Francisco (UCSF), San Francisco, CA, USA
| | - Julio C Rojas
- Department of Neurology, Memory and Aging Center, Weill Institute for Neurosciences, University of California at San Francisco (UCSF), San Francisco, CA, USA
| | - Adam L Boxer
- Department of Neurology, Memory and Aging Center, Weill Institute for Neurosciences, University of California at San Francisco (UCSF), San Francisco, CA, USA
| | - Bruce L Miller
- Department of Neurology, Memory and Aging Center, Weill Institute for Neurosciences, University of California at San Francisco (UCSF), San Francisco, CA, USA
| | - Gil D Rabinovici
- Department of Neurology, Memory and Aging Center, Weill Institute for Neurosciences, University of California at San Francisco (UCSF), San Francisco, CA, USA
| | - Joel H Kramer
- Department of Neurology, Memory and Aging Center, Weill Institute for Neurosciences, University of California at San Francisco (UCSF), San Francisco, CA, USA
| | - Kaitlin B Casaletto
- Department of Neurology, Memory and Aging Center, Weill Institute for Neurosciences, University of California at San Francisco (UCSF), San Francisco, CA, USA
| |
Collapse
|
23
|
Saha P, Sarkar S, Paidi RK, Biswas SC. TIMP-1: A key cytokine released from activated astrocytes protects neurons and ameliorates cognitive behaviours in a rodent model of Alzheimer's disease. Brain Behav Immun 2020; 87:804-819. [PMID: 32194232 DOI: 10.1016/j.bbi.2020.03.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 02/29/2020] [Accepted: 03/15/2020] [Indexed: 12/20/2022] Open
Abstract
Alzheimer's disease (AD) is characterized by two pathologic species, extracellular amyloid-β (Aβ) plaques and intracellular neurofibrillary tangles. Astrocytes that maintain normal homeostasis in the brain undergo a set of molecular, cellular and functional changes called reactive astrogliosis in various neurological diseases including AD. It is hypothesized that reactive astrocytes initially tend to protect neurons by reducing Aβ load and by secreting a plethora of cytokines, however, their functions have only been poorly investigated. Our studies on the kinetics of activation of cortical astrocytes following Aβ-exposure revealed significant level of activation as early as in 6 h. The astrocyte conditioned medium (ACM) from 6 h Aβ-treated astrocytes (Aβ-ACM) provided significant neuroprotection of cultured cortical neurons against Aβ insults. Analysis of the secreted proteins in Aβ-ACM revealed a marked increase of Tissue inhibitor of Metalloproteinase-1 (TIMP-1) within 6 h. Interestingly, we found that neutralization of TIMP-1 with antibody or knockdown with siRNA in astrocytes abolished most of the neuroprotective ability of the 6 h Aβ-ACM on Aβ-treated cultured neurons. Furthermore addition of exogenous rat recombinant TIMP-1 protein protects primary neurons from Aβ mediated toxicity. In a well characterized Aβ-infused rodent model of AD, intra-cerebroventricular administration of TIMP-1 revealed a reduction in Aβ load and apoptosis in hippocampal and cortical regions. Finally, we found that TIMP-1 can ameliorate Aβ-induced cognitive dysfunctions through restoration of Akt and its downstream pathway and maintenance of synaptic integrity. Thus, our results not only provide a functional clarity for TIMP-1, secreted by activated astrocytes, but also support it as a major candidate in cytokine-mediated therapy of AD especially at the early phase of disease progression.
Collapse
Affiliation(s)
- Pampa Saha
- Cell Biology and Physiology Division, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata 700 032, India
| | - Sukanya Sarkar
- Cell Biology and Physiology Division, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata 700 032, India
| | - Ramesh Kumar Paidi
- Cell Biology and Physiology Division, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata 700 032, India
| | - Subhas C Biswas
- Cell Biology and Physiology Division, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata 700 032, India.
| |
Collapse
|
24
|
Li KY, Gong PF, Li JT, Xu NJ, Qin S. Morphological and molecular alterations of reactive astrocytes without proliferation in cerebral cortex of an APP/PS1 transgenic mouse model and Alzheimer's patients. Glia 2020; 68:2361-2376. [PMID: 32469469 DOI: 10.1002/glia.23845] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 04/29/2020] [Accepted: 05/04/2020] [Indexed: 12/16/2022]
Abstract
Astrocytes are fundamental for maintaining brain homeostasis and are commonly involved in the progression of neurodegenerative diseases including Alzheimer's disease (AD). In response to injury or toxic material, astrocytes undergo activation that results in hypertrophy and process ramification. Although numerous studies have shown that reactive astrocytes are intimately related to the pathogenesis of AD, their characteristic features including morphological and molecular alterations that occur during different stages of AD progression remain to be elucidated. Here, we crossed astrocyte-specific reporter mice hGFAP-CreERT2;Rosa-tdTomato with APP/PS1 mice, and then used genetic tracing to characterize the morphological profiles and expression of molecular biomarkers associated with progressive β-amyloid deposits in the cortical region of AD mice. Expression of glutamine synthetase (GS) was lower in cortical reactive astrocytes, in contrast to the higher expression of glial fibrillary acidic protein, of APP/PS1 mice and AD patients relative to that in cortical astrocytes of wild-type mice and age-matched controls, respectively. GS activity was also decreased obviously in the cortex of APP/PS1 mice at 6 and 12 months of age relative to that in the wild-type mice of the same ages. Furthermore, cortical reactive astrocytes in APP/PS1 mice and AD patients did not undergo proliferation. Finally, based on RNA-sequencing analysis, we identified differentially expressed transcripts of signal transduction molecules involved in early induction of reactive astrocytes in the cortex of APP/PS1 mice. These findings provide a morphological and molecular basis with which to understand the function and mechanism of reactive astrocytes in the progression of AD.
Collapse
Affiliation(s)
- Kun-Yu Li
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Pi-Fang Gong
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Jia-Tong Li
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Nan-Jie Xu
- Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Song Qin
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| |
Collapse
|
25
|
A Role of Low-Density Lipoprotein Receptor-Related Protein 4 (LRP4) in Astrocytic Aβ Clearance. J Neurosci 2020; 40:5347-5361. [PMID: 32457076 DOI: 10.1523/jneurosci.0250-20.2020] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 05/10/2020] [Accepted: 05/16/2020] [Indexed: 01/28/2023] Open
Abstract
Amyloid-β (Aβ) deposition occurs years before cognitive symptoms appear and is considered a cause of Alzheimer's disease (AD). The imbalance of Aβ production and clearance leads to Aβ accumulation and Aβ deposition. Increasing evidence indicates an important role of astrocytes, the most abundant cell type among glial cells in the brain, in Aβ clearance. We explored the role of low-density lipoprotein receptor-related protein 4 (LRP4), a member of the LDLR family, in AD pathology. We show that Lrp4 is specifically expressed in astrocytes and its levels in astrocytes were higher than those of Ldlr and Lrp1, both of which have been implicated in Aβ uptake. LRP4 was reduced in postmortem brain tissues of AD patients. Genetic deletion of the Lrp4 gene augmented Aβ plaques in 5xFAD male mice, an AD mouse model, and exacerbated the deficits in neurotransmission, synchrony between the hippocampus and PFC, and cognition. Mechanistically, LRP4 promotes Aβ uptake by astrocytes likely by interacting with ApoE. Together, our study demonstrates that astrocytic LRP4 plays an important role in Aβ pathology and cognitive function.SIGNIFICANCE STATEMENT This study investigates how astrocytes, a type of non-nerve cells in the brain, may contribute to Alzheimer's disease (AD) development. We demonstrate that the low-density lipoprotein receptor-related protein 4 (LRP4) is reduced in the brain of AD patients. Mimicking the reduced levels in an AD mouse model exacerbates cognitive impairment and increases amyloid aggregates that are known to damage the brain. We show that LRP4 could promote the clearance of amyloid protein by astrocytes. Our results reveal a previously unappreciated role of LRP4 in AD development.
Collapse
|
26
|
Essayan-Perez S, Zhou B, Nabet AM, Wernig M, Huang YWA. Modeling Alzheimer's disease with human iPS cells: advancements, lessons, and applications. Neurobiol Dis 2019; 130:104503. [PMID: 31202913 PMCID: PMC6689423 DOI: 10.1016/j.nbd.2019.104503] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 03/24/2019] [Accepted: 06/12/2019] [Indexed: 12/11/2022] Open
Abstract
One in three people will develop Alzheimer's disease (AD) or another dementia and, despite intense research efforts, treatment options remain inadequate. Understanding the mechanisms of AD pathogenesis remains our principal hurdle to developing effective therapeutics to tackle this looming medical crisis. In light of recent discoveries from whole-genome sequencing and technical advances in humanized models, studying disease risk genes with induced human neural cells presents unprecedented advantages. Here, we first review the current knowledge of the proposed mechanisms underlying AD and focus on modern genetic insights to inform future studies. To highlight the utility of human pluripotent stem cell-based innovations, we then present an update on efforts in recapitulating the pathophysiology by induced neuronal, non-neuronal and a collection of brain cell types, departing from the neuron-centric convention. Lastly, we examine the translational potentials of such approaches, and provide our perspectives on the promise they offer to deepen our understanding of AD pathogenesis and to accelerate the development of intervention strategies for patients and risk carriers.
Collapse
Affiliation(s)
- Sofia Essayan-Perez
- Department of Molecular and Cellular Physiology, Stanford University Medical School, Stanford, CA 94305, United States of America
| | - Bo Zhou
- Department of Molecular and Cellular Physiology, Stanford University Medical School, Stanford, CA 94305, United States of America; Institute for Stem Cell Biology and Regenerative Medicine and Department of Pathology, Stanford University Medical School, Stanford, CA 94305, United States of America
| | - Amber M Nabet
- Department of Molecular and Cellular Physiology, Stanford University Medical School, Stanford, CA 94305, United States of America
| | - Marius Wernig
- Institute for Stem Cell Biology and Regenerative Medicine and Department of Pathology, Stanford University Medical School, Stanford, CA 94305, United States of America
| | - Yu-Wen Alvin Huang
- Department of Molecular and Cellular Physiology, Stanford University Medical School, Stanford, CA 94305, United States of America.
| |
Collapse
|
27
|
Schlenzig D, Cynis H, Hartlage-Rübsamen M, Zeitschel U, Menge K, Fothe A, Ramsbeck D, Spahn C, Wermann M, Roßner S, Buchholz M, Schilling S, Demuth HU. Dipeptidyl-Peptidase Activity of Meprin β Links N-truncation of Aβ with Glutaminyl Cyclase-Catalyzed pGlu-Aβ Formation. J Alzheimers Dis 2019; 66:359-375. [PMID: 30320570 DOI: 10.3233/jad-171183] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The formation of amyloid-β (Aβ) peptides is causally involved in the development of Alzheimer's disease (AD). A significant proportion of deposited Aβ is N-terminally truncated and modified at the N-terminus by a pGlu-residue (pGlu-Aβ). These forms show enhanced neurotoxicity compared to full-length Aβ. Although the truncation may occur by aminopeptidases after formation of Aβ, recently discovered processing pathways of amyloid-β protein precursor (AβPP) by proteases such as meprin β may also be involved. Here, we assessed a role of meprin β in forming Aβ3-40/42, which is the precursor of pGlu-Aβ3-40/42 generated by glutaminyl cyclase (QC). Similar to QC, meprin β mRNA is significantly upregulated in postmortem brain from AD patients. A histochemical analysis supports the presence of meprin β in neurons and astrocytes in the vicinity of pGlu-Aβ containing deposits. Cleavage of AβPP-derived peptides by meprin β in vitro results in peptides Aβ1-x, Aβ2-x, and Aβ3-x. The formation of N-truncated Aβ by meprin β was also corroborated in cell culture. A subset of the generated peptides was converted into pGlu-Aβ3-40 by an addition of glutaminyl cyclase, supporting the preceding formation of Aβ3-40. Further analysis of the meprin β cleavage revealed a yet unknown dipeptidyl-peptidase-like activity specific for the N-terminus of Aβ1-x. Thus, our data suggest that meprin β contributes to the formation of N-truncated Aβ by endopeptidase and exopeptidase activity to generate the substrate for QC-catalyzed pGlu-Aβ formation.
Collapse
Affiliation(s)
- Dagmar Schlenzig
- Department of Molecular Drug Design and Target Validation Fraunhofer Institute for Cell Therapy and Immunology, Halle (Saale), Germany
| | - Holger Cynis
- Department of Molecular Drug Design and Target Validation Fraunhofer Institute for Cell Therapy and Immunology, Halle (Saale), Germany
| | | | | | - Katja Menge
- Department of Molecular Drug Design and Target Validation Fraunhofer Institute for Cell Therapy and Immunology, Halle (Saale), Germany
| | - Anja Fothe
- Department of Molecular Drug Design and Target Validation Fraunhofer Institute for Cell Therapy and Immunology, Halle (Saale), Germany
| | - Daniel Ramsbeck
- Department of Molecular Drug Design and Target Validation Fraunhofer Institute for Cell Therapy and Immunology, Halle (Saale), Germany
| | - Claudia Spahn
- Department of Molecular Drug Design and Target Validation Fraunhofer Institute for Cell Therapy and Immunology, Halle (Saale), Germany
| | - Michael Wermann
- Department of Molecular Drug Design and Target Validation Fraunhofer Institute for Cell Therapy and Immunology, Halle (Saale), Germany
| | - Steffen Roßner
- Paul Flechsig Institute for Brain Research, Leipzig, Germany
| | - Mirko Buchholz
- Department of Molecular Drug Design and Target Validation Fraunhofer Institute for Cell Therapy and Immunology, Halle (Saale), Germany
| | - Stephan Schilling
- Department of Molecular Drug Design and Target Validation Fraunhofer Institute for Cell Therapy and Immunology, Halle (Saale), Germany
| | - Hans-Ulrich Demuth
- Department of Molecular Drug Design and Target Validation Fraunhofer Institute for Cell Therapy and Immunology, Halle (Saale), Germany
| |
Collapse
|
28
|
Kovacs GG, Lee VM, Trojanowski JQ. Protein astrogliopathies in human neurodegenerative diseases and aging. Brain Pathol 2018; 27:675-690. [PMID: 28805003 DOI: 10.1111/bpa.12536] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 06/26/2017] [Indexed: 02/06/2023] Open
Abstract
Neurodegenerative diseases are characterized by progressive dysfunction and loss of neurons associated with depositions of pathologically altered proteins showing hierarchical involvement of brain regions. The role of astrocytes in the pathogenesis of neurodegenerative diseases is explored as contributors to neuronal degeneration or neuroprotection pathways, and also as potential mediators of the transcellular spreading of disease-associated proteins. Protein astrogliopathy (PAG), including deposition of amyloid-β, prion protein, tau, α-synuclein, and very rarely transactive response DNA-binding protein 43 (TDP-43) is not unprecedented or unusual in neurodegenerative diseases. Morphological characterization of PAG is considered, however, only for the neuropathological diagnosis and classification of tauopathies. Astrocytic tau pathology is seen in primary frontotemporal lobar degeneration (FTLD) associated with tau pathologies (FTLD-Tau), and also in the form of aging-related tau astrogliopathy (ARTAG). Importantly, ARTAG shares common features with primary FTLD-Tau as well as with the astroglial tau pathologies that are thought to be hallmarks of a brain injury-related tauopathy known as chronic traumatic encephalopathy (CTE). Supported by experimental observations, the morphological variability of PAG might reflect distinct pathogenic involvement of different astrocytic populations. PAG might indicate astrocytic contribution to spreading or clearance of disease-associated proteins, however, this might lead to astrocytic dysfunction and eventually contribute to the degeneration of neurons. Here, we review recent advances in understanding ARTAG and other related forms of PAG.
Collapse
Affiliation(s)
- Gabor G Kovacs
- Institute of Neurology, Medical University of Vienna, Vienna, Austria
| | - Virginia M Lee
- Center for Neurodegenerative Disease Research, Institute on Aging and Department of Pathology and Laboratory Medicine of the Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA
| | - John Q Trojanowski
- Center for Neurodegenerative Disease Research, Institute on Aging and Department of Pathology and Laboratory Medicine of the Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA
| |
Collapse
|
29
|
Insulin-signaling Pathway Regulates the Degradation of Amyloid β-protein via Astrocytes. Neuroscience 2018; 385:227-236. [PMID: 29932983 DOI: 10.1016/j.neuroscience.2018.06.018] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Revised: 06/09/2018] [Accepted: 06/11/2018] [Indexed: 01/06/2023]
Abstract
Alzheimer's disease (AD) has been considered as a metabolic dysfunction disease associated with impaired insulin signaling. Determining the mechanisms underlying insulin signaling dysfunction and resistance in AD will be important for its treatment. Impaired clearance of amyloid-β peptide (Aβ) significantly contributes to amyloid accumulation, which is typically observed in the brain of AD patients. Reduced expression of important Aβ-degrading enzymes in the brain, such as neprilysin (NEP) and insulin-degrading enzyme (IDE), can promote Aβ deposition in sporadic late-onset AD patients. Here, we investigated whether insulin regulates the degradation of Aβ by inducing expression of NEP and IDE in cultured astrocytes. Treatment of astrocytes with insulin significantly reduced cellular NEP levels, but increased IDE expression. The effects of insulin on the expression of NEP and IDE involved activation of an extracellular signal-regulated kinase (ERK)-mediated pathway. The reduction in cellular NEP levels was associated with NEP secretion into the culture medium, whereas IDE was increased in the cell membranes. Moreover, insulin-treated astrocytes significantly facilitated the degradation of exogenous Aβ within the culture medium. Interestingly, pretreatment of astrocytes with an ERK inhibitor prior to insulin exposure markedly inhibited insulin-induced degradation of Aβ. These results suggest that insulin exposure enhanced Aβ degradation via an increase in NEP secretion and IDE expression in astrocytes, via activation of the ERK-mediated pathway. The inhibition of insulin signaling pathways delayed Aβ degradation by attenuating alterations in NEP and IDE levels and competition with insulin and Aβ. Our results provide further insight into the pathological relevance of insulin resistance in AD development.
Collapse
|
30
|
Edison P, Brooks DJ. Role of Neuroinflammation in the Trajectory of Alzheimer’s Disease and in vivo Quantification Using PET. J Alzheimers Dis 2018; 64:S339-S351. [DOI: 10.3233/jad-179929] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Paul Edison
- Neurology Imaging Unit, Department of Medicine, Imperial College London, London, UK
| | - David J. Brooks
- Department of Nuclear Medicine, Aarhus University, Denmark
- Institute of Neuroscience, University of Newcastle upon Tyne, UK
| |
Collapse
|
31
|
Garwood CJ, Ratcliffe LE, Simpson JE, Heath PR, Ince PG, Wharton SB. Review: Astrocytes in Alzheimer's disease and other age-associated dementias: a supporting player with a central role. Neuropathol Appl Neurobiol 2018; 43:281-298. [PMID: 27442752 DOI: 10.1111/nan.12338] [Citation(s) in RCA: 145] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 07/15/2016] [Accepted: 07/21/2016] [Indexed: 12/12/2022]
Abstract
Astrocytes have essential roles in the central nervous system and are also implicated in the pathogenesis of neurodegenerative disease. Forming non-overlapping domains, astrocytes are highly complex cells. Immunohistochemistry to a variety of proteins can be used to study astrocytes in tissue, labelling different cellular components and sub-populations, including glial fibrillary acidic protein, ALDH1L1, CD44, NDRG2 and amino acid transporters, but none of these labels the entire astrocyte population. Increasing heterogeneity is recognized in the astrocyte population, a complexity that is relevant both to their normal function and pathogenic roles. They are involved in neuronal support, as active components of the tripartite synapse and in cell interactions within the neurovascular unit (NVU), where they are essential for blood-brain barrier maintenance and neurovascular coupling. Astrocytes change with age, and their responses may modulate the cellular effects of neurodegenerative pathologies, which alone do not explain all of the variance in statistical models of neurodegenerative dementias. Astrocytes respond to both the neurofibrillary tangles and plaques of Alzheimer's disease, to hyperphosphorylated tau and Aβ, eliciting an effect which may be neuroprotective or deleterious. Not only astrocyte hypertrophy, in the form of gliosis, occurs, but also astrocyte injury and atrophy. Loss of normal astrocyte functions may contribute to reduced support for neurones and dysfunction of the NVU. Understanding how astrocytes contribute to dementia requires an understanding of the underlying heterogeneity of astrocyte populations, and the complexity of their responses to pathology. Enhancing the supportive and neuroprotective components of the astrocyte response has potential translational applications in therapeutic approaches to dementia.
Collapse
Affiliation(s)
- C J Garwood
- Sheffield Institute for Translational Neuroscience, Sheffield, UK
| | - L E Ratcliffe
- Sheffield Institute for Translational Neuroscience, Sheffield, UK
| | - J E Simpson
- Sheffield Institute for Translational Neuroscience, Sheffield, UK
| | - P R Heath
- Sheffield Institute for Translational Neuroscience, Sheffield, UK
| | - P G Ince
- Sheffield Institute for Translational Neuroscience, Sheffield, UK
| | - S B Wharton
- Sheffield Institute for Translational Neuroscience, Sheffield, UK
| |
Collapse
|
32
|
Perez-Nievas BG, Serrano-Pozo A. Deciphering the Astrocyte Reaction in Alzheimer's Disease. Front Aging Neurosci 2018; 10:114. [PMID: 29922147 PMCID: PMC5996928 DOI: 10.3389/fnagi.2018.00114] [Citation(s) in RCA: 174] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Accepted: 04/03/2018] [Indexed: 12/24/2022] Open
Abstract
Reactive astrocytes were identified as a component of senile amyloid plaques in the cortex of Alzheimer's disease (AD) patients several decades ago. However, their role in AD pathophysiology has remained elusive ever since, in part owing to the extrapolation of the literature from primary astrocyte cultures and acute brain injury models to a chronic neurodegenerative scenario. Recent accumulating evidence supports the idea that reactive astrocytes in AD acquire neurotoxic properties, likely due to both a gain of toxic function and a loss of their neurotrophic effects. However, the diversity and complexity of this glial cell is only beginning to be unveiled, anticipating that astrocyte reaction might be heterogeneous as well. Herein we review the evidence from mouse models of AD and human neuropathological studies and attempt to decipher the main conundrums that astrocytes pose to our understanding of AD development and progression. We discuss the morphological features that characterize astrocyte reaction in the AD brain, the consequences of astrocyte reaction for both astrocyte biology and AD pathological hallmarks, and the molecular pathways that have been implicated in this reaction.
Collapse
Affiliation(s)
| | - Alberto Serrano-Pozo
- Alzheimer's Research Unit, MassGeneral Institute for Neurodegenerative Diseases (MIND), Department of Neurology, Massachusetts General Hospital, Boston, MA, United States
| |
Collapse
|
33
|
Javidnia M, Hebron ML, Xin Y, Kinney NG, Moussa CEH. Pazopanib Reduces Phosphorylated Tau Levels and Alters Astrocytes in a Mouse Model of Tauopathy. J Alzheimers Dis 2018; 60:461-481. [PMID: 28869476 DOI: 10.3233/jad-170429] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Hyperphosphorylation and aggregation of tau protein is a critical factor in many neurodegenerative diseases. These diseases are increasing in prevalence, and there are currently no cures. Previous work from our group and others has shown that tyrosine kinase inhibitors (TKIs) can stimulate autophagy, decrease pathological proteins, and improve symptoms in models of neurodegeneration. Here we examined the role of pazopanib in mouse models that express either human mutant P301L tau (TauP301L) or triple mutant amyloid precursor protein (3x-AβPP). The TauP301L mouse expresses P301L tau under the control of a prion promoter in both neurons and astrocytes, reminiscent of some human tauopathies. Pazopanib crosses the blood-brain barrier with no detectable peripheral off-side effects, and decreases p-tau in TauP301L mice. Pazopanib reaches a brain concentration sufficient for inhibition of several tyrosine kinases, including vascular endothelial growth factor receptors (VEGFRs). Further, pazopanib does not affect microglia but reduces astrocyte levels toward nontransgenic controls in TauP301L mice. Pazopanib does not alter amyloid beta levels or astrocytes in 3x-AβPP mice but modulates a number of inflammatory markers (IP-10, MIP-1α, MIP-1β, and RANTES). These data suggest that pazopanib may be involved in p-tau clearance and modulation of astrocytic activity in models of tauopathies.
Collapse
Affiliation(s)
- Monica Javidnia
- Department of Neurology, Laboratory for Dementiaand Parkinsonism, Translational Neurotherapeutics Program, Washington, DC, USA.,Department of Pharmacologyand Physiology, Georgetown University Medical Center, Washington, DC, USA
| | - Michaeline L Hebron
- Department of Neurology, Laboratory for Dementiaand Parkinsonism, Translational Neurotherapeutics Program, Washington, DC, USA
| | - Yue Xin
- Department of Neurology, Laboratory for Dementiaand Parkinsonism, Translational Neurotherapeutics Program, Washington, DC, USA
| | - Nikolas G Kinney
- Department of Neurology, Laboratory for Dementiaand Parkinsonism, Translational Neurotherapeutics Program, Washington, DC, USA
| | - Charbel E-H Moussa
- Department of Neurology, Laboratory for Dementiaand Parkinsonism, Translational Neurotherapeutics Program, Washington, DC, USA
| |
Collapse
|
34
|
Logan S, Pharaoh GA, Marlin MC, Masser DR, Matsuzaki S, Wronowski B, Yeganeh A, Parks EE, Premkumar P, Farley JA, Owen DB, Humphries KM, Kinter M, Freeman WM, Szweda LI, Van Remmen H, Sonntag WE. Insulin-like growth factor receptor signaling regulates working memory, mitochondrial metabolism, and amyloid-β uptake in astrocytes. Mol Metab 2018; 9:141-155. [PMID: 29398615 PMCID: PMC5870102 DOI: 10.1016/j.molmet.2018.01.013] [Citation(s) in RCA: 107] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 01/11/2018] [Accepted: 01/16/2018] [Indexed: 01/01/2023] Open
Abstract
Objective A decline in mitochondrial function and biogenesis as well as increased reactive oxygen species (ROS) are important determinants of aging. With advancing age, there is a concomitant reduction in circulating levels of insulin-like growth factor-1 (IGF-1) that is closely associated with neuronal aging and neurodegeneration. In this study, we investigated the effect of the decline in IGF-1 signaling with age on astrocyte mitochondrial metabolism and astrocyte function and its association with learning and memory. Methods Learning and memory was assessed using the radial arm water maze in young and old mice as well as tamoxifen-inducible astrocyte-specific knockout of IGFR (GFAP-CreTAM/igfrf/f). The impact of IGF-1 signaling on mitochondrial function was evaluated using primary astrocyte cultures from igfrf/f mice using AAV-Cre mediated knockdown using Oroboros respirometry and Seahorse assays. Results Our results indicate that a reduction in IGF-1 receptor (IGFR) expression with age is associated with decline in hippocampal-dependent learning and increased gliosis. Astrocyte-specific knockout of IGFR also induced impairments in working memory. Using primary astrocyte cultures, we show that reducing IGF-1 signaling via a 30–50% reduction IGFR expression, comparable to the physiological changes in IGF-1 that occur with age, significantly impaired ATP synthesis. IGFR deficient astrocytes also displayed altered mitochondrial structure and function and increased mitochondrial ROS production associated with the induction of an antioxidant response. However, IGFR deficient astrocytes were more sensitive to H2O2-induced cytotoxicity. Moreover, IGFR deficient astrocytes also showed significantly impaired glucose and Aβ uptake, both critical functions of astrocytes in the brain. Conclusions Regulation of astrocytic mitochondrial function and redox status by IGF-1 is essential to maintain astrocytic function and coordinate hippocampal-dependent spatial learning. Age-related astrocytic dysfunction caused by diminished IGF-1 signaling may contribute to the pathogenesis of Alzheimer's disease and other age-associated cognitive pathologies. Altered mitochondrial structure and function with IGFR deficiency in astrocytes is proposed. Increased reactive oxygen species production and susceptibility to peroxide induced cytotoxicity. Decreased Aβ uptake and impairment in spatial working memory.
Collapse
Affiliation(s)
- Sreemathi Logan
- Reynold's Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, USA.
| | - Gavin A Pharaoh
- Department of Physiology, University of Oklahoma Health Sciences Center, USA; Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, USA
| | - M Caleb Marlin
- Graduate College, University of Oklahoma Health Sciences Center, USA
| | - Dustin R Masser
- Reynold's Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, USA; Department of Physiology, University of Oklahoma Health Sciences Center, USA
| | - Satoshi Matsuzaki
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, USA; Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, USA
| | - Benjamin Wronowski
- Reynold's Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, USA; Department of Physiology, University of Oklahoma Health Sciences Center, USA
| | - Alexander Yeganeh
- Reynold's Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, USA; Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, USA
| | - Eileen E Parks
- Reynold's Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, USA; Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, USA
| | - Pavithra Premkumar
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, USA
| | - Julie A Farley
- Reynold's Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, USA
| | - Daniel B Owen
- Reynold's Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, USA
| | - Kenneth M Humphries
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, USA; Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, USA
| | - Michael Kinter
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, USA
| | - Willard M Freeman
- Reynold's Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, USA; Department of Physiology, University of Oklahoma Health Sciences Center, USA; Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, USA
| | - Luke I Szweda
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, USA; Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, USA
| | - Holly Van Remmen
- Department of Physiology, University of Oklahoma Health Sciences Center, USA; Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, USA; Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, USA
| | - William E Sonntag
- Reynold's Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, USA; Department of Physiology, University of Oklahoma Health Sciences Center, USA; Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, USA
| |
Collapse
|
35
|
Abstract
Alzheimer disease neuropathology is characterized by the extracellular accumulation of Aβ peptide and intracellular aggregation of hyperphosphorylated tau. With the progression of the disease, macroscopic atrophy affects the entorhinal area and hippocampus, amygdala, and associative regions of the neocortex. The locus coeruleus is depigmented. The deposition of Aβ is first made of diffuse deposits. Amyloid focal deposits constitute the core of the senile plaque which also comprises a corona of tau-positive neurites. Aβ deposits are found successively in the neocortex, the hippocampus, the striatum, the mesencephalon, and finally the cerebellum together with the pontine nuclei (Thal phases). Tau pathology affects in a stereotyped order some specific nuclei of the brainstem, the entorhinal area, the hippocampus, and the neocortex - first the associative areas and secondarily the primary cortices (Braak stages). Loss of synapses is observed in association with tau and Aβ pathology; neuronal loss occurs in the most affected areas. Granulovacuolar degeneration and perisomatic granules are also linked to Alzheimer disease pathology. The physiopathology of Alzheimer disease remains unknown. Familial cases suggest that Aβ deposition is the initial step, but tau pathology appears early in the course and seems to be better correlated with the symptoms.
Collapse
Affiliation(s)
- Ana Laura Calderon-Garcidueñas
- Raymond Escourolle Neuropathology Department. Groupe Hospitalier Pitié-Salpêtrière, Paris, France; Instituto de Medicina Forense, Universidad Veracruzana, Boca del Río, Mexico
| | - Charles Duyckaerts
- Raymond Escourolle Neuropathology Department. Groupe Hospitalier Pitié-Salpêtrière, Paris, France; Alzheimer-Prion Research Team, Institut du Cerveau et de la Moelle (ICM), Paris, France.
| |
Collapse
|
36
|
Yang H, Wang Y, Kar S. Effects of cholesterol transport inhibitor U18666A on APP metabolism in rat primary astrocytes. Glia 2017; 65:1728-1743. [PMID: 28722194 DOI: 10.1002/glia.23191] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 06/27/2017] [Accepted: 06/27/2017] [Indexed: 12/21/2022]
Abstract
Amyloid β (Aβ) peptides generated from the amyloid precursor protein (APP) play an important role in the degeneration of neurons and development of Alzheimer's disease (AD). Current evidence indicates that high levels of cholesterol-which increase the risk of developing AD-can influence Aβ production in neurons. However, it remains unclear how altered level/subcellular distribution of cholesterol in astrocytes can influence APP metabolism. In this study, we evaluated the effects of cholesterol transport inhibitor U18666A-a class II amphiphile that triggers redistribution of cholesterol within the endosomal-lysosomal (EL) system-on APP levels and metabolism in rat primary cultured astrocytes. Our results revealed that U18666A increased the levels of the APP holoprotein and its cleaved products (α-/β-/η-CTFs) in cultured astrocytes, without altering the total levels of cholesterol or cell viability. The cellular levels of Aβ1-40 were also found to be markedly increased, while secretory levels of Aβ1-40 were decreased in U18666A-treated astrocytes. We further report a corresponding increase in the activity of the enzymes regulating APP processing, such as α-secretase, β-secretase, and γ-secretase as a consequence of U18666A treatment. Additionally, APP-cleaved products are partly accumulated in the lysosomes following cholesterol sequestration within EL system possibly due to decreased clearance. Interestingly, serum delipidation attenuated enhanced levels of APP and its cleaved products following U18666A treatment. Collectively, these results suggest that cholesterol sequestration within the EL system in astrocytes can influence APP metabolism and the accumulation of APP-cleaved products including Aβ peptides, which can contribute to the development of AD pathology.
Collapse
Affiliation(s)
- Hongyan Yang
- Department of Psychiatry, Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, T6G 2M8, Canada
- Department of Pharmacology, Qiqihar Medical University, Qiqihar, Heilongjiang, China
| | - Yanlin Wang
- Department of Psychiatry, Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, T6G 2M8, Canada
| | - Satyabrata Kar
- Department of Psychiatry, Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, T6G 2M8, Canada
- Department of Medicine, Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, T6G 2M8, Canada
| |
Collapse
|
37
|
Ferrer I. Diversity of astroglial responses across human neurodegenerative disorders and brain aging. Brain Pathol 2017; 27:645-674. [PMID: 28804999 PMCID: PMC8029391 DOI: 10.1111/bpa.12538] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 05/24/2017] [Indexed: 12/11/2022] Open
Abstract
Astrogliopathy refers to alterations of astrocytes occurring in diseases of the nervous system, and it implies the involvement of astrocytes as key elements in the pathogenesis and pathology of diseases and injuries of the central nervous system. Reactive astrocytosis refers to the response of astrocytes to different insults to the nervous system, whereas astrocytopathy indicates hypertrophy, atrophy/degeneration and loss of function and pathological remodeling occurring as a primary cause of a disease or as a factor contributing to the development and progression of a particular disease. Reactive astrocytosis secondary to neuron loss and astrocytopathy due to intrinsic alterations of astrocytes occur in neurodegenerative diseases, overlap each other, and, together with astrocyte senescence, contribute to disease-specific astrogliopathy in aging and neurodegenerative diseases with abnormal protein aggregates in old age. In addition to the well-known increase in glial fibrillary acidic protein and other proteins in reactive astrocytes, astrocytopathy is evidenced by deposition of abnormal proteins such as β-amyloid, hyper-phosphorylated tau, abnormal α-synuclein, mutated huntingtin, phosphorylated TDP-43 and mutated SOD1, and PrPres , in Alzheimer's disease, tauopathies, Lewy body diseases, Huntington's disease, amyotrophic lateral sclerosis and Creutzfeldt-Jakob disease, respectively. Astrocytopathy in these diseases can also be manifested by impaired glutamate transport; abnormal metabolism and release of neurotransmitters; altered potassium, calcium and water channels resulting in abnormal ion and water homeostasis; abnormal glucose metabolism; abnormal lipid and, particularly, cholesterol metabolism; increased oxidative damage and altered oxidative stress responses; increased production of cytokines and mediators of the inflammatory response; altered expression of connexins with deterioration of cell-to-cell networks and transfer of gliotransmitters; and worsening function of the blood brain barrier, among others. Increased knowledge of these aspects will permit a better understanding of brain aging and neurodegenerative diseases in old age as complex disorders in which neurons are not the only players.
Collapse
Affiliation(s)
- Isidro Ferrer
- Department of Pathology and Experimental TherapeuticsUniversity of BarcelonaBarcelonaSpain
- Institute of NeuropathologyPathologic Anatomy Service, Bellvitge University Hospital, IDIBELL, Hospitalet de LlobregatBarcelonaSpain
- Institute of NeurosciencesUniversity of BarcelonaBarcelonaSpain
- Biomedical Network Research Center on Neurodegenerative Diseases (CIBERNED), Institute Carlos IIIMadridSpain
| |
Collapse
|
38
|
Crompton LA, Cordero‐Llana O, Caldwell MA. Astrocytes in a dish: Using pluripotent stem cells to model neurodegenerative and neurodevelopmental disorders. Brain Pathol 2017; 27:530-544. [PMID: 28585380 PMCID: PMC8028895 DOI: 10.1111/bpa.12522] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 04/27/2017] [Indexed: 02/06/2023] Open
Abstract
Neuroscience and Neurobiology have historically been neuron biased, yet up to 40% of the cells in the brain are astrocytes. These cells are heterogeneous and regionally diverse but universally essential for brain homeostasis. Astrocytes regulate synaptic transmission as part of the tripartite synapse, provide metabolic and neurotrophic support, recycle neurotransmitters, modulate blood flow and brain blood barrier permeability and are implicated in the mechanisms of neurodegeneration. Using pluripotent stem cells (PSC), it is now possible to study regionalised human astrocytes in a dish and to model their contribution to neurodevelopmental and neurodegenerative disorders. The evidence challenging the traditional neuron-centric view of degeneration within the CNS is reviewed here, with focus on recent findings and disease phenotypes from human PSC-derived astrocytes. In addition we compare current protocols for the generation of regionalised astrocytes and how these can be further refined by our growing knowledge of neurodevelopment. We conclude by proposing a functional and phenotypical characterisation of PSC-derived astrocytic cultures that is critical for reproducible and robust disease modelling.
Collapse
Affiliation(s)
- Lucy A. Crompton
- School of Biochemistry, Medical Sciences BldUniversity of BristolBristolBS8 1TDUK
| | - Oscar Cordero‐Llana
- Bristol Medical School, Medical Sciences BldUniversity of BristolBristolBS8 1TDUK
| | - Maeve A. Caldwell
- Trinity College Institute for NeuroscienceTrinity College Dublin 2Ireland
| |
Collapse
|
39
|
Boscia F, Pannaccione A, Ciccone R, Casamassa A, Franco C, Piccialli I, de Rosa V, Vinciguerra A, Di Renzo G, Annunziato L. The expression and activity of K V3.4 channel subunits are precociously upregulated in astrocytes exposed to Aβ oligomers and in astrocytes of Alzheimer's disease Tg2576 mice. Neurobiol Aging 2017; 54:187-198. [PMID: 28390823 DOI: 10.1016/j.neurobiolaging.2017.03.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 03/06/2017] [Accepted: 03/07/2017] [Indexed: 12/12/2022]
Abstract
Astrocyte dysfunction emerges early in Alzheimer's disease (AD) and may contribute to its pathology and progression. Recently, the voltage gated potassium channel KV3.4 subunit, which underlies the fast-inactivating K+ currents, has been recognized to be relevant for AD pathogenesis and is emerging as a new target candidate for AD. In the present study, we investigated both in in vitro and in vivo models of AD the expression and functional activity of KV3.4 potassium channel subunits in astrocytes. In primary astrocytes our biochemical, immunohistochemical, and electrophysiological studies demonstrated a time-dependent upregulation of KV3.4 expression and functional activity after exposure to amyloid-β (Aβ) oligomers. Consistently, astrocytic KV3.4 expression was upregulated in the cerebral cortex, hippocampus, and cerebellum of 6-month-old Tg2576 mice. Further, confocal triple labeling studies revealed that in 6-month-old Tg2576 mice, KV3.4 was intensely coexpressed with Aβ in nonplaque associated astrocytes. Interestingly, in the cortical and hippocampal regions of 12-month-old Tg2576 mice, plaque-associated astrocytes much more intensely expressed KV3.4 subunits, but not Aβ. More important, we evidenced that the selective knockdown of KV3.4 expression significantly downregulated both glial fibrillary acidic protein levels and Aβ trimers in the brain of 6-month-old Tg2576 mice. Collectively, our results demonstrate that the expression and function of KV3.4 channel subunits are precociously upregulated in cultured astrocytes exposed to Aβ oligomers and in reactive astrocytes of AD Tg2576 mice.
Collapse
Affiliation(s)
- Francesca Boscia
- Division of Pharmacology, Department of Neuroscience, Reproductive and Odontostomatological Sciences, School of Medicine, "Federico II" University of Naples, Naples, Italy
| | - Anna Pannaccione
- Division of Pharmacology, Department of Neuroscience, Reproductive and Odontostomatological Sciences, School of Medicine, "Federico II" University of Naples, Naples, Italy
| | - Roselia Ciccone
- Division of Pharmacology, Department of Neuroscience, Reproductive and Odontostomatological Sciences, School of Medicine, "Federico II" University of Naples, Naples, Italy
| | - Antonella Casamassa
- Division of Pharmacology, Department of Neuroscience, Reproductive and Odontostomatological Sciences, School of Medicine, "Federico II" University of Naples, Naples, Italy
| | - Cristina Franco
- Division of Pharmacology, Department of Neuroscience, Reproductive and Odontostomatological Sciences, School of Medicine, "Federico II" University of Naples, Naples, Italy
| | - Ilaria Piccialli
- Division of Pharmacology, Department of Neuroscience, Reproductive and Odontostomatological Sciences, School of Medicine, "Federico II" University of Naples, Naples, Italy
| | - Valeria de Rosa
- Division of Pharmacology, Department of Neuroscience, Reproductive and Odontostomatological Sciences, School of Medicine, "Federico II" University of Naples, Naples, Italy
| | - Antonio Vinciguerra
- Division of Pharmacology, Department of Neuroscience, Reproductive and Odontostomatological Sciences, School of Medicine, "Federico II" University of Naples, Naples, Italy
| | - Gianfranco Di Renzo
- Division of Pharmacology, Department of Neuroscience, Reproductive and Odontostomatological Sciences, School of Medicine, "Federico II" University of Naples, Naples, Italy
| | - Lucio Annunziato
- Division of Pharmacology, Department of Neuroscience, Reproductive and Odontostomatological Sciences, School of Medicine, "Federico II" University of Naples, Naples, Italy; Fondazione IRCCS SDN, Naples, Italy.
| |
Collapse
|
40
|
Hunter S, Brayne C. Erratum to: Do anti-amyloid beta protein antibody cross reactivities confound Alzheimer disease research? J Negat Results Biomed 2017; 16:8. [PMID: 28274242 PMCID: PMC5343297 DOI: 10.1186/s12952-017-0073-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Affiliation(s)
- Sally Hunter
- Department of Public Health and Primary Care, Institute of Public Health Forvie Site, University of Cambridge School of Clinical Medicine, Box 113 Cambridge Biomedical Campus, Cambridge, CB2 0SP, UK.
| | - Carol Brayne
- Department of Public Health and Primary Care, Institute of Public Health Forvie Site, University of Cambridge School of Clinical Medicine, Box 113 Cambridge Biomedical Campus, Cambridge, CB2 0SP, UK
| |
Collapse
|
41
|
Huynh TPV, Davis AA, Ulrich JD, Holtzman DM. Apolipoprotein E and Alzheimer's disease: the influence of apolipoprotein E on amyloid-β and other amyloidogenic proteins. J Lipid Res 2017; 58:824-836. [PMID: 28246336 DOI: 10.1194/jlr.r075481] [Citation(s) in RCA: 134] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Revised: 02/25/2017] [Indexed: 12/13/2022] Open
Abstract
Alzheimer's disease (AD) is one of the fastest-growing causes of death and disability in persons 65 years of age or older, affecting more than 5 million Americans alone. Clinical manifestations of AD include progressive decline in memory, executive function, language, and other cognitive domains. Research efforts within the last three decades have identified APOE as the most significant genetic risk factor for late-onset AD, which accounts for >99% of cases. The apoE protein is hypothesized to affect AD pathogenesis through a variety of mechanisms, from its effects on the blood-brain barrier, the innate immune system, and synaptic function to the accumulation of amyloid-β (Aβ). Here, we discuss the role of apoE on the biophysical properties and metabolism of the Aβ peptide, the principal component of amyloid plaques and cerebral amyloid angiopathy (CAA). CAA is characterized by the deposition of amyloid proteins (including Aβ) in the leptomeningeal medium and small arteries, which is found in most AD cases but sometimes occurs as an independent entity. Accumulation of these pathologies in the brain is one of the pathological hallmarks of AD. Beyond Aβ, we will extend the discussion to the potential role of apoE on other amyloidogenic proteins found in AD, and also a number of diverse neurodegenerative diseases.
Collapse
Affiliation(s)
- Tien-Phat V Huynh
- Department of Neurology, Hope Center for Neurological Disorders, Knight Alzheimer's Disease Research Center, Washington University, St. Louis, MO 63110
| | - Albert A Davis
- Department of Neurology, Hope Center for Neurological Disorders, Knight Alzheimer's Disease Research Center, Washington University, St. Louis, MO 63110
| | - Jason D Ulrich
- Department of Neurology, Hope Center for Neurological Disorders, Knight Alzheimer's Disease Research Center, Washington University, St. Louis, MO 63110
| | - David M Holtzman
- Department of Neurology, Hope Center for Neurological Disorders, Knight Alzheimer's Disease Research Center, Washington University, St. Louis, MO 63110
| |
Collapse
|
42
|
Dossi E, Vasile F, Rouach N. Human astrocytes in the diseased brain. Brain Res Bull 2017; 136:139-156. [PMID: 28212850 PMCID: PMC5766741 DOI: 10.1016/j.brainresbull.2017.02.001] [Citation(s) in RCA: 154] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 02/08/2017] [Accepted: 02/09/2017] [Indexed: 12/23/2022]
Abstract
Astrocytes are key active elements of the brain that contribute to information processing. They not only provide neurons with metabolic and structural support, but also regulate neurogenesis and brain wiring. Furthermore, astrocytes modulate synaptic activity and plasticity in part by controlling the extracellular space volume, as well as ion and neurotransmitter homeostasis. These findings, together with the discovery that human astrocytes display contrasting characteristics with their rodent counterparts, point to a role for astrocytes in higher cognitive functions. Dysfunction of astrocytes can thereby induce major alterations in neuronal functions, contributing to the pathogenesis of several brain disorders. In this review we summarize the current knowledge on the structural and functional alterations occurring in astrocytes from the human brain in pathological conditions such as epilepsy, primary tumours, Alzheimer's disease, major depressive disorder and Down syndrome. Compelling evidence thus shows that dysregulations of astrocyte functions and interplay with neurons contribute to the development and progression of various neurological diseases. Targeting astrocytes is thus a promising alternative approach that could contribute to the development of novel and effective therapies to treat brain disorders.
Collapse
Affiliation(s)
- Elena Dossi
- Neuroglial Interactions in Cerebral Physiopathology, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University, Paris, France.
| | - Flora Vasile
- Neuroglial Interactions in Cerebral Physiopathology, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University, Paris, France.
| | - Nathalie Rouach
- Neuroglial Interactions in Cerebral Physiopathology, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University, Paris, France.
| |
Collapse
|
43
|
Hunter S, Brayne C. Do anti-amyloid beta protein antibody cross reactivities confound Alzheimer disease research? J Negat Results Biomed 2017; 16:1. [PMID: 28126004 PMCID: PMC5270220 DOI: 10.1186/s12952-017-0066-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 01/13/2017] [Indexed: 12/20/2022] Open
Abstract
Background Alzheimer disease (AD) research has focussed mainly on the amyloid beta protein (Aβ). However, many Aβ-and P3-type peptides derived from the amyloid precursor protein (APP) and peptides thought to derive from Aβ catabolism share sequence homology. Additionally, conformations can change dependent on aggregation state and solubility leading to significant uncertainty relating to interpretations of immunoreactivity with antibodies raised against Aβ. We review evidence relating to the reactivities of commonly used antibodies including 6F3D, 6E10 and 4G8 and evaluate their reactivity profiles with respect to AD diagnosis and research. Results Antibody cross-reactivities between Aβ-type, P3-type and Aβ-catabolic peptides confound interpretations of immunoreactivity. More than one antibody is required to adequately characterise Aβ. The relationships between anti-Aβ immunoreactivity, neuropathology and proposed APP cleavages are unclear. Conclusions We find that the concept of Aβ lacks clarity as a specific entity. Anti-Aβ antibody cross-reactivities lead to significant uncertainty in our understanding of the APP proteolytic system and its role in AD with profound implications for current research and therapeutic strategies.
Collapse
Affiliation(s)
- Sally Hunter
- Department of Public Health and Primary Care, Institute of Public Health Forvie Site, University of Cambridge School of Clinical Medicine, Box 113 Cambridge Biomedical Campus, Cambridge, CB2 0SP, UK.
| | - Carol Brayne
- Department of Public Health and Primary Care, Institute of Public Health Forvie Site, University of Cambridge School of Clinical Medicine, Box 113 Cambridge Biomedical Campus, Cambridge, CB2 0SP, UK
| |
Collapse
|
44
|
Iram T, Trudler D, Kain D, Kanner S, Galron R, Vassar R, Barzilai A, Blinder P, Fishelson Z, Frenkel D. Astrocytes from old Alzheimer's disease mice are impaired in Aβ uptake and in neuroprotection. Neurobiol Dis 2016; 96:84-94. [DOI: 10.1016/j.nbd.2016.08.001] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 07/11/2016] [Accepted: 08/16/2016] [Indexed: 10/21/2022] Open
|
45
|
Gleixner AM, Posimo JM, Pant DB, Henderson MP, Leak RK. Astrocytes Surviving Severe Stress Can Still Protect Neighboring Neurons from Proteotoxic Injury. Mol Neurobiol 2016; 53:4939-60. [PMID: 26374549 PMCID: PMC4792804 DOI: 10.1007/s12035-015-9427-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 09/03/2015] [Indexed: 12/18/2022]
Abstract
Astrocytes are one of the major cell types to combat cellular stress and protect neighboring neurons from injury. In order to fulfill this important role, astrocytes must sense and respond to toxic stimuli, perhaps including stimuli that are severely stressful and kill some of the astrocytes. The present study demonstrates that primary astrocytes that managed to survive severe proteotoxic stress were protected against subsequent challenges. These findings suggest that the phenomenon of preconditioning or tolerance can be extended from mild to severe stress for this cell type. Astrocytic stress adaptation lasted at least 96 h, the longest interval tested. Heat shock protein 70 (Hsp70) was raised in stressed astrocytes, but inhibition of neither Hsp70 nor Hsp32 activity abolished their resistance against a second proteotoxic challenge. Only inhibition of glutathione synthesis abolished astrocytic stress adaptation, consistent with our previous report. Primary neurons were plated upon previously stressed astrocytes, and the cocultures were then exposed to another proteotoxic challenge. Severely stressed astrocytes were still able to protect neighboring neurons against this injury, and the protection was unexpectedly independent of glutathione synthesis. Stressed astrocytes were even able to protect neurons after simultaneous application of proteasome and Hsp70 inhibitors, which otherwise elicited synergistic, severe loss of neurons when applied together. Astrocyte-induced neuroprotection against proteotoxicity was not elicited with astrocyte-conditioned media, suggesting that physical cell-to-cell contacts may be essential. These findings suggest that astrocytes may adapt to severe stress so that they can continue to protect neighboring cell types from profound injury.
Collapse
Affiliation(s)
- Amanda M Gleixner
- Division of Pharmaceutical Sciences, Mylan School of Pharmacy, Duquesne University, 407 Mellon Hall, 600 Forbes Avenue, Pittsburgh, PA, 15282, USA
| | - Jessica M Posimo
- Division of Pharmaceutical Sciences, Mylan School of Pharmacy, Duquesne University, 407 Mellon Hall, 600 Forbes Avenue, Pittsburgh, PA, 15282, USA
| | - Deepti B Pant
- Division of Pharmaceutical Sciences, Mylan School of Pharmacy, Duquesne University, 407 Mellon Hall, 600 Forbes Avenue, Pittsburgh, PA, 15282, USA
| | - Matthew P Henderson
- Division of Pharmaceutical Sciences, Mylan School of Pharmacy, Duquesne University, 407 Mellon Hall, 600 Forbes Avenue, Pittsburgh, PA, 15282, USA
| | - Rehana K Leak
- Division of Pharmaceutical Sciences, Mylan School of Pharmacy, Duquesne University, 407 Mellon Hall, 600 Forbes Avenue, Pittsburgh, PA, 15282, USA.
| |
Collapse
|
46
|
Söllvander S, Nikitidou E, Brolin R, Söderberg L, Sehlin D, Lannfelt L, Erlandsson A. Accumulation of amyloid-β by astrocytes result in enlarged endosomes and microvesicle-induced apoptosis of neurons. Mol Neurodegener 2016; 11:38. [PMID: 27176225 PMCID: PMC4865996 DOI: 10.1186/s13024-016-0098-z] [Citation(s) in RCA: 163] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 04/15/2016] [Indexed: 01/22/2023] Open
Abstract
Background Despite the clear physical association between activated astrocytes and amyloid-β (Aβ) plaques, the importance of astrocytes and their therapeutic potential in Alzheimer’s disease remain elusive. Soluble Aβ aggregates, such as protofibrils, have been suggested to be responsible for the widespread neuronal cell death in Alzheimer’s disease, but the mechanisms behind this remain unclear. Moreover, ineffective degradation is of great interest when it comes to the development and progression of neurodegeneration. Based on our previous results that astrocytes are extremely slow in degrading phagocytosed material, we hypothesized that astrocytes may be an important player in these processes. Hence, the aim of this study was to clarify the role of astrocytes in clearance, spreading and neuronal toxicity of Aβ. Results To examine the role of astrocytes in Aβ pathology, we added Aβ protofibrils to a co-culture system of primary neurons and glia. Our data demonstrates that astrocytes rapidly engulf large amounts of Aβ protofibrils, but then store, rather than degrade the ingested material. The incomplete digestion results in a high intracellular load of toxic, partly N-terminally truncated Aβ and severe lysosomal dysfunction. Moreover, secretion of microvesicles containing N-terminally truncated Aβ, induce apoptosis of cortical neurons. Conclusions Taken together, our results suggest that astrocytes play a central role in the progression of Alzheimer’s disease, by accumulating and spreading toxic Aβ species. Electronic supplementary material The online version of this article (doi:10.1186/s13024-016-0098-z) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Sofia Söllvander
- Department of Public Health & Caring Sciences/Molecular Geriatrics, Rudbeck Laboratory, Uppsala University, SE-751 85, Uppsala, Sweden
| | - Elisabeth Nikitidou
- Department of Public Health & Caring Sciences/Molecular Geriatrics, Rudbeck Laboratory, Uppsala University, SE-751 85, Uppsala, Sweden
| | - Robin Brolin
- Department of Public Health & Caring Sciences/Molecular Geriatrics, Rudbeck Laboratory, Uppsala University, SE-751 85, Uppsala, Sweden
| | - Linda Söderberg
- BioArctic Neuroscience AB, Warfvinges väg 35, SE-112 51, Stockholm, Sweden
| | - Dag Sehlin
- Department of Public Health & Caring Sciences/Molecular Geriatrics, Rudbeck Laboratory, Uppsala University, SE-751 85, Uppsala, Sweden
| | - Lars Lannfelt
- Department of Public Health & Caring Sciences/Molecular Geriatrics, Rudbeck Laboratory, Uppsala University, SE-751 85, Uppsala, Sweden
| | - Anna Erlandsson
- Department of Public Health & Caring Sciences/Molecular Geriatrics, Rudbeck Laboratory, Uppsala University, SE-751 85, Uppsala, Sweden.
| |
Collapse
|
47
|
Astrogliosis: An integral player in the pathogenesis of Alzheimer's disease. Prog Neurobiol 2016; 144:121-41. [PMID: 26797041 DOI: 10.1016/j.pneurobio.2016.01.001] [Citation(s) in RCA: 186] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 11/10/2015] [Accepted: 01/10/2016] [Indexed: 12/15/2022]
Abstract
Alzheimer's disease is the main cause of dementia in the elderly and begins with a subtle decline in episodic memory followed by a more general decline in overall cognitive abilities. Though the exact trigger for this cascade of events remains unknown the presence of the misfolded amyloid-beta protein triggers reactive gliosis, a prominent neuropathological feature in the brains of Alzheimer's patients. The cytoskeletal and morphological changes of astrogliosis are its evident features, while changes in oxidative stress defense, cholesterol metabolism, and gene transcription programs are less manifest. However, these latter molecular changes may underlie a disruption in homeostatic regulation that keeps the brain environment balanced. Astrocytes in Alzheimer's disease show changes in glutamate and GABA signaling and recycling, potassium buffering, and in cholinergic, purinergic, and calcium signaling. Ultimately the dysregulation of homeostasis maintained by astrocytes can have grave consequences for the stability of microcircuits within key brain regions. Specifically, altered inhibition influenced by astrocytes can lead to local circuit imbalance with farther reaching consequences for the functioning of larger neuronal networks. Healthy astrocytes have a role in maintaining and modulating normal neuronal communication, synaptic physiology and energy metabolism, astrogliosis interferes with these functions. This review considers the molecular and functional changes occurring during astrogliosis in Alzheimer's disease, and proposes that astrocytes are key players in the development of dementia.
Collapse
|
48
|
Rosenberger AFN, Morrema THJ, Gerritsen WH, van Haastert ES, Snkhchyan H, Hilhorst R, Rozemuller AJM, Scheltens P, van der Vies SM, Hoozemans JJM. Increased occurrence of protein kinase CK2 in astrocytes in Alzheimer's disease pathology. J Neuroinflammation 2016; 13:4. [PMID: 26732432 PMCID: PMC4702323 DOI: 10.1186/s12974-015-0470-x] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 12/24/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Alzheimer's disease (AD) is the most common neurodegenerative disease. In addition to the occurrence of amyloid deposits and widespread tau pathology, AD is associated with a neuroinflammatory response characterized by the activation of microglia and astrocytes. Protein kinase 2 (CK2, former casein kinase II) is involved in a wide variety of cellular processes. Previous studies on CK2 in AD showed controversial results, and the involvement of CK2 in neuroinflammation in AD remains elusive. METHODS In this study, we used immunohistochemical and immunofluorescent staining methods to investigate the localization of CK2 in the hippocampus and temporal cortex of patients with AD and non-demented controls. We compared protein levels with Western blotting analysis, and we investigated CK2 activity in human U373 astrocytoma cells and human primary adult astrocytes stimulated with IL-1β or TNF-α. RESULTS We report increased levels of CK2 in the hippocampus and temporal cortex of AD patients compared to non-demented controls. Immunohistochemical analysis shows CK2 immunoreactivity in astrocytes in AD and control cases. In AD, the presence of CK2 immunoreactive astrocytes is increased. CK2 immunopositive astrocytes are associated with amyloid deposits, suggesting an involvement of CK2 in the neuroinflammatory response. In U373 cells and human primary astrocytes, the selective CK2 inhibitor CX-4945 shows a dose-dependent reduction of the IL-1β or TNF-α induced MCP-1 and IL-6 secretion. CONCLUSIONS This data suggests that CK2 in astrocytes is involved in the neuroinflammatory response in AD. The reduction in pro-inflammatory cytokine secretion by human astrocytes using the selective CK2 inhibitor CX-4945 indicates that CK2 could be a potential target to modulate neuroinflammation in AD.
Collapse
Affiliation(s)
- Andrea F N Rosenberger
- Alzheimer center & Department of Neurology, Neuroscience Campus Amsterdam, VU University Medical Center, De Boelelaan 1118, 1081 HZ, Amsterdam, The Netherlands.
- Department of Pathology, Neuroscience Campus Amsterdam, VU University Medical Center, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
| | - Tjado H J Morrema
- Department of Pathology, Neuroscience Campus Amsterdam, VU University Medical Center, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
| | - Wouter H Gerritsen
- Department of Pathology, Neuroscience Campus Amsterdam, VU University Medical Center, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
| | - Elise S van Haastert
- Department of Pathology, Neuroscience Campus Amsterdam, VU University Medical Center, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
| | - Hripsime Snkhchyan
- Department of Pathology, Neuroscience Campus Amsterdam, VU University Medical Center, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
| | - Riet Hilhorst
- PamGene International BV, Wolvenhoek 10, 5211 HH, 's-Hertogenbosch, The Netherlands.
| | - Annemieke J M Rozemuller
- Department of Pathology, Neuroscience Campus Amsterdam, VU University Medical Center, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
| | - Philip Scheltens
- Alzheimer center & Department of Neurology, Neuroscience Campus Amsterdam, VU University Medical Center, De Boelelaan 1118, 1081 HZ, Amsterdam, The Netherlands.
| | - Saskia M van der Vies
- Department of Pathology, Neuroscience Campus Amsterdam, VU University Medical Center, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
| | - Jeroen J M Hoozemans
- Department of Pathology, Neuroscience Campus Amsterdam, VU University Medical Center, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
| |
Collapse
|
49
|
Kokiko-Cochran O, Ransohoff L, Veenstra M, Lee S, Saber M, Sikora M, Teknipp R, Xu G, Bemiller S, Wilson G, Crish S, Bhaskar K, Lee YS, Ransohoff RM, Lamb BT. Altered Neuroinflammation and Behavior after Traumatic Brain Injury in a Mouse Model of Alzheimer's Disease. J Neurotrauma 2015; 33:625-40. [PMID: 26414955 DOI: 10.1089/neu.2015.3970] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Traumatic brain injury (TBI) has acute and chronic sequelae, including an increased risk for the development of Alzheimer's disease (AD). TBI-associated neuroinflammation is characterized by activation of brain-resident microglia and infiltration of monocytes; however, recent studies have implicated beta-amyloid as a major manipulator of the inflammatory response. To examine neuroinflammation after TBI and development of AD-like features, these studies examined the effects of TBI in the presence and absence of beta-amyloid. The R1.40 mouse model of cerebral amyloidosis was used, with a focus on time points well before robust AD pathologies. Unexpectedly, in R1.40 mice, the acute neuroinflammatory response to TBI was strikingly muted, with reduced numbers of CNS myeloid cells acquiring a macrophage phenotype and decreased expression of inflammatory cytokines. At chronic time points, macrophage activation substantially declined in non-Tg TBI mice; however, it was relatively unchanged in R1.40 TBI mice. The persistent inflammatory response coincided with significant tissue loss between 3 and 120 days post-injury in R1.40 TBI mice, which was not observed in non-Tg TBI mice. Surprisingly, inflammatory cytokine expression was enhanced in R1.40 mice compared with non-Tg mice, regardless of injury group. Although R1.40 TBI mice demonstrated task-specific deficits in cognition, overall functional recovery was similar to non-Tg TBI mice. These findings suggest that accumulating beta-amyloid leads to an altered post-injury macrophage response at acute and chronic time points. Together, these studies emphasize the role of post-injury neuroinflammation in regulating long-term sequelae after TBI and also support recent studies implicating beta-amyloid as an immunomodulator.
Collapse
Affiliation(s)
| | - Lena Ransohoff
- 1 Department of Neurosciences, Cleveland Clinic , Cleveland, Ohio
| | - Mike Veenstra
- 1 Department of Neurosciences, Cleveland Clinic , Cleveland, Ohio
| | - Sungho Lee
- 1 Department of Neurosciences, Cleveland Clinic , Cleveland, Ohio
| | - Maha Saber
- 1 Department of Neurosciences, Cleveland Clinic , Cleveland, Ohio
| | - Matt Sikora
- 1 Department of Neurosciences, Cleveland Clinic , Cleveland, Ohio
| | - Ryan Teknipp
- 1 Department of Neurosciences, Cleveland Clinic , Cleveland, Ohio
| | - Guixiang Xu
- 1 Department of Neurosciences, Cleveland Clinic , Cleveland, Ohio
| | - Shane Bemiller
- 1 Department of Neurosciences, Cleveland Clinic , Cleveland, Ohio
| | - Gina Wilson
- 2 Department of Pharmaceutical Science, Northeast Ohio Medical University , Rootstown, Ohio
| | - Samuel Crish
- 2 Department of Pharmaceutical Science, Northeast Ohio Medical University , Rootstown, Ohio
| | - Kiran Bhaskar
- 3 Department of Molecular Genetics Microbiology and Neurology, University of New Mexico , Albuquerque New Mexico
| | - Yu-Shang Lee
- 1 Department of Neurosciences, Cleveland Clinic , Cleveland, Ohio
| | | | - Bruce T Lamb
- 1 Department of Neurosciences, Cleveland Clinic , Cleveland, Ohio.,5 Department of Genetics and Department of Neurosciences, Case Western Reserve University , Cleveland, Ohio
| |
Collapse
|
50
|
Avila-Muñoz E, Arias C. Cholesterol-induced astrocyte activation is associated with increased amyloid precursor protein expression and processing. Glia 2015; 63:2010-2022. [PMID: 26096015 DOI: 10.1002/glia.22874] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Revised: 05/22/2015] [Accepted: 06/01/2015] [Indexed: 11/05/2022]
Abstract
Cholesterol is essential for maintaining lipid raft integrity and has been regarded as a crucial regulatory factor for amyloidogenesis in Alzheimer's disease (AD). The vast majority of studies on amyloid precursor protein (APP) metabolism and amyloid β-protein (Aβ) production have focused on neurons. The role of astrocytes remains largely unexplored, despite the presence of activated astrocytes in the brains of most patients with AD and in transgenic models of the disease. The role of cholesterol in Aβ production has been thoroughly studied in neurons and attributed to the participation of lipid rafts in APP metabolism. Thus, in this study, we analyzed the effect of cholesterol loading in astrocytes and analyzed the expression and processing of APP. We found that cholesterol exposure induced astrocyte activation, increased APP content, and enhanced the interaction of APP with BACE-1. These effects were associated with an enrichment of ganglioside GM1-cholesterol patches in the astrocyte membrane and with increased ROS production. GLIA 2015;63:2010-2022.
Collapse
Affiliation(s)
- Evangelina Avila-Muñoz
- Departamento De Medicina Genómica Y Toxicología Ambiental, Instituto De Investigaciones Biomédicas, Universidad Nacional Autónoma De México, D.F., México
| | - Clorinda Arias
- Departamento De Medicina Genómica Y Toxicología Ambiental, Instituto De Investigaciones Biomédicas, Universidad Nacional Autónoma De México, D.F., México
| |
Collapse
|