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Updated: Jun 7, 2026
Quantitative 3D In Silico Modeling (q3DISM) of Cerebral Amyloid-beta Phagocytosis in Rodent Models of Alzheimer's Disease
Published on: December 26, 2016
Microglial CD31 suppresses Aβ clearance and promotes Alzheimer pathology in 5×FAD mice
Qiuzhi Zhou1,2,3, Fei Sun1, Yao Zhang4
1Key Laboratory of Education Ministry of China/Hubei Province for Neurological Disorders, Department of Pathophysiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Abstract:
Microglia play crucial roles in Alzheimer's disease (AD), yet the molecular mechanisms are unclear. Here, we show that CD31, a recognized endothelial marker, is predominantly expressed in microglia but not in neurons or astrocytes, and it is significantly elevated in the brains of AD patients and mouse models. Microglia-specific CD31 knockdown in 5xFAD mice substantially attenuated the dysregulated transcription networks, suppressed microglia hyperactivation and the disease-associated microglia (DAM), mitigated Aβ deposition and inflammation, and eventually improved cognitive functions in mice. Mechanistically, CD31 knockdown damaged the simultaneous recruitment of Src homology phosphatase 2 (SHP2) and STAT3, leading to a reduced dephosphorylation and enhanced activation of STAT3, a transcription factor. STAT3 activation increased transcription of membrane metalloendopeptidase (MME) and promoted Aβ clearance. Collectively, this study identifies microglial CD31, by regulating SHP2-STAT3-MME axis, plays a role in AD pathogenesis and targeting CD31 is promising in AD drug development.
Insights
Microglia’s CD31 protein is elevated in Alzheimer's disease (AD). Reducing CD31 in mice improved cognition by modulating microglia activation and amyloid-beta clearance, suggesting CD31 as a therapeutic target for AD.
Area of Science:
- Neuroscience
- Immunology
- Molecular Biology
Background:
- Microglia are key players in Alzheimer's disease (AD) pathogenesis.
- The precise molecular mechanisms involving microglia in AD remain incompletely understood.
- CD31, typically an endothelial marker, is found on microglia in AD brains.
Purpose of the Study:
- To investigate the role of microglial CD31 in Alzheimer's disease.
- To elucidate the molecular pathways regulated by CD31 in microglia.
- To evaluate CD31 as a potential therapeutic target for AD.
Main Methods:
- Expression analysis of CD31 in AD patients and mouse models.
- Microglia-specific CD31 knockdown in 5xFAD mouse models of AD.
- Assessment of transcriptional networks, microglia activation states, amyloid-beta deposition, inflammation, and cognitive function.
- Mechanistic studies involving SHP2, STAT3, and MME signaling pathways.
Main Results:
- CD31 is significantly elevated in microglia in AD brains.
- Microglia-specific CD31 knockdown attenuated disease-associated microglia (DAM) phenotypes, reduced neuroinflammation and Aβ deposition, and improved cognitive function in 5xFAD mice.
- CD31 knockdown disrupted SHP2-STAT3 recruitment, leading to enhanced STAT3 activation, increased MME transcription, and improved Aβ clearance.
Conclusions:
- Microglial CD31 plays a significant role in AD pathogenesis.
- The SHP2-STAT3-MME signaling axis is regulated by CD31 in microglia.
- Targeting microglial CD31 presents a promising therapeutic strategy for Alzheimer's disease drug development.
