Microglial immunophenotype in dementia with Alzheimer's pathology
Thais Minett1,2, John Classey3, Fiona E Matthews4
1Institute of Public Health, Department of Public Health and Primary Care, University of Cambridge, Cambridge, CB1 8RN, UK.
Journal of Neuroinflammation
|June 4, 2016
Summary
Microglia, the brain's immune cells, show reduced motility (Iba1) in Alzheimer's disease dementia. Increased expression of other markers (CD68, MSR-A) correlates with pathology and cognitive decline, suggesting complex microglial roles.
Area of Science:
- Neuroscience
- Immunology
- Pathology
Background:
- Genetic risk factors suggest inflammation is key in Alzheimer's disease (AD).
- Microglia, brain macrophages, survey the brain via motile processes.
Purpose of the Study:
- To investigate microglial roles in dementia with Alzheimer's pathology.
- To immunophenotype microglia in post-mortem brain tissue.
Main Methods:
- Analyzed cerebral cortex from 299 participants using immunohistochemistry.
- Assessed markers: CD68 (phagocytosis), HLA-DR (antigen presentation), Iba1 (motility), MSR-A (plaque phagocytosis), CD64 (Fc receptor).
Main Results:
- Dementia associated with increased CD68, MSR-A, CD64 and decreased Iba1.
- Cognitive function correlated with Iba1 (positively) and CD68 (negatively) in non-demented individuals.
- Alzheimer's pathology linked to microglial markers differently in demented vs. non-demented groups.
- APOE ε2 associated with Iba1/MSR-A; APOE ε4 with CD68/HLA-DR/CD64.
Conclusions:
- Microglia may lose motility (Iba1) in AD dementia, impairing neuronal support.
- Increased microglial clearance markers (CD68, MSR-A) associate with AD pathology and cognitive decline.
- Microglial responses to AD pathology are complex and vary with dementia status, potentially influencing disease development.
