Functional impairment of microglia coincides with Beta-amyloid deposition in mice with Alzheimer-like pathology
Grietje Krabbe1, Annett Halle, Vitali Matyash
1Max Delbrueck Center for Molecular Medicine (MDC), Berlin, Germany.
Abstract:
Microglial cells closely interact with senile plaques in Alzheimer's disease and acquire the morphological appearance of an activated phenotype. The significance of this microglial phenotype and the impact of microglia for disease progression have remained controversial. To uncover and characterize putative changes in the functionality of microglia during Alzheimer's disease, we directly assessed microglial behavior in two mouse models of Alzheimer's disease. Using in vivo two-photon microscopy and acute brain slice preparations, we found that important microglial functions - directed process motility and phagocytic activity - were strongly impaired in mice with Alzheimer's disease-like pathology compared to age-matched non-transgenic animals. Notably, impairment of microglial function temporally and spatially correlated with Aβ plaque deposition, and phagocytic capacity of microglia could be restored by interventionally decreasing amyloid burden by Aβ vaccination. These data suggest that major microglial functions progressively decline in Alzheimer's disease with the appearance of Aβ plaques, and that this functional impairment is reversible by lowering Aβ burden, e.g. by means of Aβ vaccination.
Insights
Microglial (immune cell) functions like motility and phagocytosis decline in Alzheimer's disease due to amyloid plaques. This impairment is reversible with amyloid-beta vaccination, suggesting a potential therapeutic strategy.
Area of Science:
- Neuroscience
- Immunology
- Cell Biology
Background:
- Microglial cells, the brain's immune cells, interact with amyloid plaques in Alzheimer's disease (AD).
- The role and functional impact of activated microglia in AD pathogenesis remain debated.
- Understanding microglial dysfunction is crucial for AD therapeutic development.
Purpose of the Study:
- To investigate functional changes in microglia during Alzheimer's disease progression.
- To characterize the impact of amyloid-beta (Aβ) plaques on microglial activity.
- To explore the reversibility of microglial dysfunction.
Main Methods:
- Utilized two-photon microscopy in vivo and acute brain slice preparations.
- Assessed microglial directed process motility and phagocytic activity in AD mouse models.
- Correlated microglial function with amyloid plaque deposition and Aβ vaccination outcomes.
Main Results:
- Key microglial functions, including process motility and phagocytosis, were significantly impaired in AD mouse models.
- Microglial functional decline correlated temporally and spatially with Aβ plaque accumulation.
- Aβ vaccination restored microglial phagocytic capacity by reducing amyloid burden.
Conclusions:
- Major microglial functions progressively decline with amyloid plaque deposition in Alzheimer's disease.
- This functional impairment is directly linked to the amyloid burden.
- Reducing amyloid burden, for example, through Aβ vaccination, can restore microglial function, offering a potential therapeutic avenue.
