Related Experiment Video
Updated: Oct 11, 2026
Quantitative 3D In Silico Modeling q3DISM of Cerebral Amyloid-beta Phagocytosis in Rodent Models of Alzheimer's Disease
Published on: December 26, 2016
Different effects of constitutive and induced microbiota modulation on microglia in a mouse model of Alzheimer's
Charlotte Mezö1,2, Nikolaos Dokalis1,2, Omar Mossad1,2
1Institute of Neuropathology, University of Freiburg, Breisacher Str. 64, 79106, Freiburg, Germany.
Abstract:
It was recently revealed that gut microbiota promote amyloid-beta (Aβ) burden in mouse models of Alzheimer's disease (AD). However, the underlying mechanisms when using either germ-free (GF) housing conditions or treatments with antibiotics (ABX) remained unknown. In this study, we show that GF and ABX-treated 5x familial AD (5xFAD) mice developed attenuated hippocampal Aβ pathology and associated neuronal loss, and thereby delayed disease-related memory deficits. While Aβ production remained unaffected in both GF and ABX-treated 5xFAD mice, we noticed in GF 5xFAD mice enhanced microglial Aβ uptake at early stages of the disease compared to ABX-treated 5xFAD mice. Furthermore, RNA-sequencing of hippocampal microglia from SPF, GF and ABX-treated 5xFAD mice revealed distinct microbiota-dependent gene expression profiles associated with phagocytosis and altered microglial activation states. Taken together, we observed that constitutive or induced microbiota modulation in 5xFAD mice differentially controls microglial Aβ clearance mechanisms preventing neurodegeneration and cognitive deficits.
Insights
Gut microbes worsen Alzheimer's disease (AD) by increasing amyloid-beta (Aβ). Modulating gut bacteria in AD mice reduced Aβ plaque, neurodegeneration, and memory loss by enhancing microglial clearance.
Area of Science:
- Neuroscience
- Microbiology
- Immunology
Background:
- Gut microbiota influence amyloid-beta (Aβ) burden in Alzheimer's disease (AD) mouse models.
- Mechanisms by which germ-free (GF) or antibiotic (ABX) treatments impact AD pathology are not fully understood.
Purpose of the Study:
- To investigate the role of gut microbiota in modulating AD pathogenesis in 5x familial AD (5xFAD) mice.
- To elucidate the mechanisms underlying microbiota-dependent control of Aβ pathology and neurodegeneration.
Main Methods:
- Comparison of Aβ pathology, neuronal loss, and cognitive function in GF, ABX-treated, and specific pathogen-free (SPF) 5xFAD mice.
- Analysis of Aβ production and microglial Aβ uptake.
- RNA-sequencing of hippocampal microglia to assess gene expression profiles.
Main Results:
- GF and ABX-treated 5xFAD mice exhibited reduced hippocampal Aβ pathology, neuronal loss, and delayed memory deficits.
- Aβ production was unchanged, but GF mice showed enhanced microglial Aβ uptake compared to ABX-treated mice.
- Microbiota modulation led to distinct, microbiota-dependent microglial gene expression profiles related to phagocytosis and activation states.
Conclusions:
- Constitutive or induced gut microbiota modulation differentially impacts microglial Aβ clearance in 5xFAD mice.
- Targeting gut microbiota can prevent neurodegeneration and cognitive decline in AD models by enhancing microglial phagocytosis.
More Related Videos
10:21Characterization and Isolation of Mouse Primary Microglia by Density Gradient Centrifugation
Published on: February 16, 2018
10:40Immunofluorescence Staining Using IBA1 and TMEM119 for Microglial Density, Morphology and Peripheral Myeloid Cell Infiltration Analysis in Mouse Brain
Published on: October 27, 2019
Related Concept Videos
01:22Gut-Brain Axis
01:21Microbiota Modulation by Antibiotics