Fatty Acid Amide Hydrolase (FAAH) Inhibition Modulates Amyloid-Beta-Induced Microglia Polarization

Area of Science:

• Neuroscience
• Immunology
• Pharmacology

Background:

• Microglial dysfunction contributes to Alzheimer's disease (AD) pathology.
• The endocannabinoid system, particularly anandamide (AEA) and its degrading enzyme fatty acid amide hydrolase (FAAH), is implicated in neuroinflammation.
• Targeting microglial phenotype is a potential therapeutic strategy for AD.

Purpose of the Study:

• To investigate if the FAAH inhibitor URB597 can modulate microglial polarization and cytoskeleton reorganization induced by amyloid-beta (Aβ) peptide.
• To assess the effects of URB597 on microglial morphology, Rho/Cdc42 protein activation, cell migration, and phagocytosis in the context of Aβ exposure.

Main Methods:

• Utilized BV-2 microglial cell line exposed to amyloid-beta (Aβ) peptide.
• Administered the FAAH inhibitor URB597.
• Performed morphological evaluation, assessed Rho and Cdc42 protein activation, measured cell migration, and quantified phagocytic activity.
• Analyzed the expression of inflammatory markers (iNOS, pro-inflammatory cytokines) and anti-inflammatory markers (Arg-1, anti-inflammatory cytokines).

Main Results:

• Aβ treatment altered BV-2 cell morphology, increasing surface area and promoting a flattened shape.
• URB597 partially reversed Aβ-induced morphological changes and reduced Rho activation and cell migration.
• URB597 increased the phagocytic activity of BV-2 cells.
• URB597 treatment polarized microglia towards an anti-inflammatory phenotype, decreasing iNOS and pro-inflammatory cytokines while increasing Arg-1 and anti-inflammatory cytokines.

Conclusions:

• FAAH inhibition by URB597 promotes cytoskeleton reorganization, regulates microglial phagocytosis and migration, and drives polarization towards an anti-inflammatory phenotype.
• These findings suggest that targeting FAAH could be a viable therapeutic approach for neuroinflammatory conditions like Alzheimer's disease by modulating microglial function.