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Updated: Jun 11, 2026
Characterization and Isolation of Mouse Primary Microglia by Density Gradient Centrifugation
Published on: February 16, 2018
Ischemic injury triggers a protective microglial phenotype in models of Aβ pathology
Michael Candlish1, Jan Hofmann1, Desirée Brösamle2,3,4,5
1Neurovascular Disorders, Institute of Cell Biology and Neuroscience, Biologicum, Goethe University Frankfurt, Max-von-Laue Str. 13, Frankfurt am Main, Germany.
Abstract:
Microglia are highly plastic cells that are capable of integrating subsequent insults. As the majority of Alzheimer's Disease (AD) patients also show cerebrovascular pathology, we here aimed to dissect the interactions between AD and ischemic brain injury on the microglial response to amyloid beta (Aβ) pathology. Unexpectedly, ischemic stroke in the context of cerebral β-amyloidosis drives the emergence of a neuroprotective microglial phenotype characterized by an ApoE-enriched transcriptional state and enhanced lipid handling. These microglia promote the rapid formation of highly compact Aβ plaques that are relatively inert and strikingly reminiscent of those observed in cognitively resilient AD patients. Our findings thus reveal that the microglial response to Aβ pathology is not a fixed trajectory toward dysfunction, but retains a capacity for beneficial reprogramming when engaged by the appropriate stimulus. Beyond characterizing this comorbid state, our data identify specific molecular pathways, centered on ApoE, complement activation, and lysosomal processing, that may be amenable to therapeutic targeting to promote protective microglial function in AD.
Insights
Ischemic stroke reprograms microglia in Alzheimer's Disease (AD) models, promoting a neuroprotective phenotype. This response enhances lipid handling and compact amyloid-beta plaque formation, suggesting therapeutic potential for AD.
Area of Science:
- Neuroscience
- Immunology
- Pathology
Background:
- Microglia, the brain's immune cells, exhibit plasticity and can respond to multiple insults.
- Alzheimer's Disease (AD) frequently co-occurs with cerebrovascular pathology, such as ischemic stroke.
- Understanding the interplay between AD and ischemic injury in microglial response to amyloid-beta (Aβ) is crucial.
Purpose of the Study:
- To investigate the impact of ischemic stroke on microglial responses in the context of cerebral β-amyloidosis.
- To characterize the microglial phenotype and its functional consequences in comorbid AD and ischemic injury.
Main Methods:
- Utilized models of cerebral β-amyloidosis and induced ischemic stroke.
- Analyzed microglial transcriptional states and lipid handling capabilities.
- Assessed the impact of microglial phenotype on amyloid-beta plaque morphology and characteristics.
Main Results:
- Ischemic stroke induced a neuroprotective microglial phenotype characterized by ApoE enrichment and enhanced lipid handling.
- These reprogrammed microglia promoted the formation of compact, relatively inert amyloid-beta plaques.
- This phenotype resembled that observed in cognitively resilient AD patients.
Conclusions:
- Microglial response to Aβ pathology is adaptable and can be beneficially reprogrammed by stimuli like ischemic stroke.
- Specific pathways involving ApoE, complement activation, and lysosomal processing are implicated in this protective microglial function.
- Targeting these pathways may offer therapeutic strategies to enhance protective microglial functions in Alzheimer's Disease.
