Serum amyloid A drive microglia shift to a resolving phenotype through Nrf2

Area of Science:

• Neuroscience
• Immunology
• Molecular Biology

Background:

• Serum amyloid A (SAA) is an acute-phase protein with diagnostic potential.
• The role of SAA in microglial activation is debated.
• Microglial activation is critical in neuroinflammation and neurodegenerative diseases.

Purpose of the Study:

• To elucidate the functional role of SAA in microglial activation.
• To investigate SAA's effects on neuroprotection in Parkinson's disease models.

Main Methods:

• Investigated SAA's effect on microglial polarization.
• Analyzed the role of Nuclear factor erythroid 2-related factor 2 (Nrf2) and the AMPK/mTOR pathway.
• Utilized in vitro neuronal cultures and an in vivo mouse model of Parkinson's disease (MPTP-induced).

Main Results:

• SAA induces pro-resolving M2 microglial polarization via Nrf2 stabilization.
• The AMPK/mTOR pathway mediates SAA-induced Nrf2 upregulation.
• SAA protects neurons from MPP+-induced damage and attenuates MPTP-induced dopaminergic neurodegeneration in mice, improving motor function.

Conclusions:

• SAA regulates microglial activation through Nrf2 stabilization, promoting a pro-resolving phenotype.
• SAA demonstrates neuroprotective effects against Parkinson's disease pathology.
• SAA represents a potential therapeutic target for Parkinson's disease.