Fig. 9: Neuronal CXCR2 contributes to mechanical allodynia, joint inflammation, and gait impairments in gout arthritis model mice.

A, B Changes in 50% PWT (A) and ankle joint diameter (B) of Cxcr2^fl/fl and SNS-Cre Cxcr2^fl/fl group of mice upon gout arthritis model establishment. C Summary of MPO activity assay. D Representative FACS plots of neutrophils (CD11b⁺Ly6G⁺) in ankle joint articular cavity from Cxcr2^fl/fl and SNS-Cre Cxcr2^fl/fl mice 8 h after intraarticular MSU/Veh injection. E Summarized % of neutrophils (CD11b⁺Ly6G⁺) within gated cell populations. F Representative histograms comparing the mean fluorescence intensity (MFI) of Ly6G expression on gated cells from Cxcr2^fl/fl+Veh (Top), Cxcr2^fl/fl + MSU (mid), or SNS-Cre Cxcr2^fl/fl + MSU (Bottom) group of mice. G Quantification of the results from panel (F). H, I CGRP and SP in ankle joint tissues of three groups of mice. J Representative photos of Ly6G-GFP signals in periarticular tissues of the ankle joint. DAPI was in purple. Scale bar = 50 µm. K Summary of the number of Ly6G-GFP⁺ cells/mm² in four groups. BIBN (60 ng/site) or L-733060 (1 μg/site) was co-applied (i.a.) with MSU. L MPO activity assays of ankle joints from four groups. M Gene expression of certain key inflammatory cytokines or chemokines in ankle joints. N Summarized gait parameters, including ration (RH/LH) of stance, paw area, stride length, and swing. *p < 0.05, **p < 0.01. Two-way ANOVA (repeated measures) with Bonferroni’s post hoc test for panels (A and B). One-way ANOVA with Bonferroni’s post hoc test for others. Data are shown as mean ± SEM. The n number, exact p-value, and statistical results are provided in the Source Data file.