Microglia maintain homeostasis in the central nervous system through phagocytic clearance of protein aggregates and cellular debris. This function deteriorates during ageing and neurodegenerative disease, concomitant with cognitive decline. However, the mechanisms of impaired microglial homeostatic function and the cognitive effects of restoring this function remain unknown. We combined CRISPR-Cas9 knockout screens with RNA sequencing analysis to discover age-related genetic modifiers of microglial phagocytosis. These screens identified CD22, a canonical B cell receptor, as a negative regulator of phagocytosis that is upregulated on aged microglia. CD22 mediates the anti-phagocytic effect of α2,6-linked sialic acid, and inhibition of CD22 promotes the clearance of myelin debris, amyloid-β oligomers and α-synuclein fibrils in vivo. Long-term central nervous system delivery of an antibody that blocks CD22 function reprograms microglia towards a homeostatic transcriptional state and improves cognitive function in aged mice. These findings elucidate a mechanism of age-related microglial impairment and a strategy to restore homeostasis in the ageing brain.
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http://dx.doi.org/10.1038/s41586-019-1088-4 | DOI Listing |
FEBS J
December 2024
Department of Neuroinflammation, UCL Queen Square Institute of Neurology, University College London, UK.
The microglial triggering receptor expressed on myeloid cells 2 (TREM2) is required for diverse microglia responses in neurodegeneration, including immunometabolic plasticity, phagocytosis, and survival. We previously identified that patient iPSC-derived microglia (iPS-Mg) harboring the Alzheimer's disease (AD) TREM2 hypomorph display several functional deficits linked to metabolism. To investigate whether these deficits are associated with disruptions in metabolite signaling, we generated common variant, TREM2 and TREM2 variant human iPS-Mg.
View Article and Find Full Text PDFJ Lipid Res
December 2024
Department of Endocrinology and Metabolism, Shunde Hospital of Southern Medical University (The First People's Hospital of Shunde Foshan), Foshan, Guangdong Province, China. Electronic address:
High-fat diet (HFD) -induced microglial activation contributes to hypothalamic inflammation and obesity, but the mechanisms linking microglia to structural changes remain unclear. This study explored the role of microglia in impairing hypothalamic synaptic plasticity in diet-induced obesity (DIO) mice and evaluated the therapeutic potential of semaglutide (Sema) and minocycline (MI). Six-week-old C57BL/6J mice were divided into low-fat diet (LFD) and HFD groups.
View Article and Find Full Text PDFGlia
December 2024
Molecular and Cellular Pharmacology Program, Stony Brook, New York, USA.
Chronic stress is a major contributor to the development of major depressive disorder, one of the leading causes of disability worldwide. Using a model of repeated social defeat stress in mice, we and others have reported that neuroinflammation plays a dynamic role in the development of behavioral deficits consistent with social avoidance and impaired reward responses. Animals susceptible to the model also exhibit hypomyelination in the medial prefrontal cortex, indicative of changes in the differentiation pathway of cells of the oligodendroglial lineage (OLN).
View Article and Find Full Text PDFBrain
December 2024
Neuroimmunology Program, Fundació Clínic per la Recerca Biomèdica - Institut d'Investigacions Biomèdiques August Pi i Sunyer (FCRB-IDIBAPS), Barcelona 08036, Spain.
Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a disorder mediated by autoantibodies against the GluN1 subunit of NMDAR. It occurs with severe neuropsychiatric symptoms that often improve with immunotherapy. Clinical studies and animal models based on patients' antibody transfer or NMDAR immunization suggest that the autoantibodies play a major pathogenic role.
View Article and Find Full Text PDFFront Cell Neurosci
December 2024
Department of Molecular Biosciences, Centre for Radiation Protection Research, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden.
Introduction And Methods: Aiming to evaluate safety aspects of a recently proposed approach to target Alzheimer's disease, we mimicked a complex boron neutron capture therapy field using a mixed beam consisting of high- and low-linear energy transfer (LET) radiation, Am alpha particles (α) and/or X-ray radiation respectively, in human microglial (HMC3) cells.
Results: Acute exposure to 2 Gy X-rays induced the strongest response in the formation of γH2AX foci 30 min post irradiation, while α- and mixed beam-induced damage (α:X-ray = 3:1) sustained longer. Fractionation of the same total dose (0.
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