Uric acid alleviates the inflammatory response in LPS-induced BV2 cells and MPTP-induced PD mice by resisting ferroptosis through the Nrf2 signalling pathway

Background: Neuroinflammation, oxidative stress, and Ferroptosis are implicated in Parkinson' s disease (PD) pathogenesis. Epidemiological studies suggest that elevated uric acid (UA) levels may reduce PD risk, but the precise molecular mechanisms involved remain unclear. In this study, we investigated the effects of UA in lipopolysaccharide (LPS) or MPP+-stimulated BV2 microglia and MPTP-induced PD mouse models.

Methods: BV2 cells are recognized as a standardized and reproducible neural inflammatory cell model for mechanism exploration. The anti-ferroptosis and anti-inflammatory effects of UA were assessed in LPS or MPP+ stimulated BV2 microglia and in an MPTP-induced PD mouse model. Western blot, qPCR, ELISA, and immunofluorescence were used to analyse the expression of inflammasome-related markers. ROS, MDA, GSH, and Fe²⁺ levels were measured using testing kits, while mitochondrial ultrastructure was evaluated through transmission electron microscopy. PD-related markers were assessed by ethology and immunohistochemistry. The Nrf2 inhibitor ML385 was employed to validate pathway specificity.

Results: We found that UA treatment reduced the expression of proinflammatory cytokines (TNF-α, IL-6, and IL-1β), ROS production, lipid peroxidation, and intracellular Fe²⁺ in BV2 microglia while increasing the antioxidant capacity and preserving the mitochondrial ultrastructure. In MPTP-treated mice, UA improved motor performance, preserved dopaminergic neuron density in the substantia nigra, and reduced neuroinflammation. UA activated Nrf2 signalling and upregulated GPX4 expression, which were attenuated by ML385, confirming the Nrf2 dependence of these effects.

Conclusion: UA alleviates Ferroptosis and neuroinflammation in LPS or MPP+ stimulated BV2 microglia and MPTP-induced PD mouse models through the activation of the Nrf2 signalling pathway.