MS4A6A/Ms4a6d deficiency disrupts neuroprotective microglia functions and promotes inflammation in Alzheimer's

Hai-Shan Jiao1, Yi-Jun Ge1, Liang-Yu Huang2

  • 1Department of Neurology and National Center for Neurological Disorders, Huashan Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Shanghai Medical College, Fudan University, National Center for Neurological Disorders, 12Th Wulumuqi Zhong Road, Shanghai, 200040, China.

PubMed
Abstract

Insights

Genetic variations in MS4A6A impact Alzheimer's disease (AD) risk. Boosting MS4A6A may offer a novel therapeutic strategy by enhancing amyloid clearance and reducing neuroinflammation in AD patients.

Area of Science:

  • Neuroscience
  • Genetics
  • Immunology

Background:

  • Alzheimer's disease (AD) is the most common dementia, with genetic factors influencing risk.
  • Microglia-associated genes, including MS4A6A, are implicated in AD pathogenesis.
  • Elevated MS4A6A levels and their correlation with neuropathology suggest a role in AD, yet the underlying mechanisms remain unelucidated.

Purpose of the Study:

  • To investigate the association between MS4A6A gene polymorphisms and Alzheimer's disease (AD) risk.
  • To explore the functional role of MS4A6A in AD pathogenesis, particularly concerning microglial function and neuroinflammation.
  • To evaluate the therapeutic potential of modulating MS4A6A in AD.

Main Methods:

  • Meta-genome-wide association analysis of 734,121 subjects to identify MS4A6A polymorphisms linked to AD risk.
  • Correlation analysis of MS4A6A expression with cerebrospinal fluid AD biomarkers in a human cohort.
  • Generation and analysis of a Ms4a6d-deficient APP/PS1 mouse model using microscopy, biochemistry, and behavioral assessments.

Main Results:

  • Identified novel MS4A6A mutations associated with altered AD risk and cerebrospinal fluid β-amyloid levels.
  • Demonstrated that Ms4a6d deficiency in mice impairs amyloid clearance by microglia, increasing plaque burden and synaptic damage.
  • Showed that Ms4a6d deficiency exacerbates neuroinflammation by disinhibiting NF-κB signaling in microglia and astrocytes.

Conclusions:

  • Ms4a6d deficiency impairs neuroprotection and exacerbates neuroinflammation in Alzheimer's disease models.
  • Sufficient Ms4a6d expression enhances microglial amyloid clearance and suppresses inflammation, suggesting therapeutic potential.
  • Elevated MS4A6A in AD patients may be compensatory; boosting MS4A6A presents a promising therapeutic strategy for Alzheimer's disease.