Abstract
Microglia are the immune cells of the brain. Here we show a massive infiltration of highly ramified and elongated microglia within the core of amyloid plaques in transgenic mouse models of Alzheimer's disease (AD). Many of these cells originate from the bone marrow, and the beta-amyloid-40 and -42 isoforms are able to trigger this chemoattraction. These newly recruited cells also exhibit a specific immune reaction to both exogenous and endogenous beta-amyloid in the brain. Creation of a new AD transgenic mouse that expresses the thymidine kinase protein under the control of the CD11b promoter allowed us to show that blood-derived microglia and not their resident counterparts have the ability to eliminate amyloid deposits by a cell-specific phagocytic mechanism. These bone marrow-derived microglia are thus very efficient in restricting amyloid deposits. Therapeutic strategies aiming to improve their recruitment could potentially lead to a new powerful tool for the elimination of toxic senile plaques.
Publication types
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Comparative Study
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Research Support, Non-U.S. Gov't
MeSH terms
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Age Factors
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Alzheimer Disease / genetics
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Alzheimer Disease / metabolism*
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Alzheimer Disease / pathology*
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Amyloid beta-Peptides / pharmacology
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Amyloid beta-Protein Precursor / genetics
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Amyloid beta-Protein Precursor / metabolism
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Animals
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Bone Marrow Cells / physiology*
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Bone Marrow Transplantation / methods
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Calcium-Binding Proteins / metabolism
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Cells, Cultured
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Disease Models, Animal
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Gene Expression / drug effects
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Green Fluorescent Proteins / genetics
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Green Fluorescent Proteins / metabolism
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Humans
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Imaging, Three-Dimensional / methods
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Immunohistochemistry / methods
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In Situ Hybridization / methods
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Indoles
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Injections, Intraventricular / methods
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Interleukin-1 / metabolism
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Lysosomal-Associated Membrane Protein 2 / metabolism
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Membrane Cofactor Protein / metabolism
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Membrane Proteins / genetics
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Membrane Proteins / metabolism
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Mice
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Mice, Inbred C57BL
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Mice, Transgenic
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Microfilament Proteins
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Microglia / drug effects
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Microglia / physiology*
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Microscopy, Confocal / methods
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Peptide Fragments / pharmacology
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Phagocytosis / physiology
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Plaque, Amyloid / metabolism
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Plaque, Amyloid / pathology*
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Presenilin-1
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RNA, Messenger / metabolism
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Time Factors
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Toll-Like Receptor 2 / metabolism
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Tumor Necrosis Factor-alpha / metabolism
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Whole-Body Irradiation / methods
Substances
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Aif1 protein, mouse
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Amyloid beta-Peptides
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Amyloid beta-Protein Precursor
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Calcium-Binding Proteins
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Indoles
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Interleukin-1
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Lysosomal-Associated Membrane Protein 2
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Mcp protein, mouse
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Membrane Cofactor Protein
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Membrane Proteins
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Microfilament Proteins
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PSEN1 protein, human
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Peptide Fragments
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Presenilin-1
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RNA, Messenger
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Tlr2 protein, mouse
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Toll-Like Receptor 2
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Tumor Necrosis Factor-alpha
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amyloid beta-protein (1-42)
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Green Fluorescent Proteins
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DAPI