Fig. 3: IDO-Gal3 protects against upregulation of inflammatory gene expression and joint structural changes from load-induced osteoarthritis.

a, A 4-week cyclic mechanical overloading PTOA mouse model was utilized in mice treated weekly with intra-articular IDO-Gal3 injections. b,c, Knee explant fluorescence imaging illustrating (b) and quantifying (c) day 7 retention of fluorescently labelled IDO and IDO-Gal3 administered after 2 weeks of mechanical loading. d, AUC pharmacokinetic analysis from daily fluorescent imaging over 7 d. e–h, Gene expression of cytokines IL-6 and IL-12p40 was measured by quantitative PCR in combined joint tissue of synovial wall and articular surface (e,f) and draining lymph nodes (g,h). i,j, H&E-stained joint histology on knees highlighting synovial inflammation and thickening (i) and DJD scoring of joint disease progression (j). k,l, Safranin O histological stain highlighting structure changes and proteoglycan content of the articular cartilage (k) and OARSI scoring of cartilage structure (l). Data in j and l shown as mean ± 95% C.I. Statistical analysis: (c,d) Student’s t-test, n = 6. For e–h: one-way ANOVA with Tukey’s post-hoc test; n = 6. For e, P = 0.0035, F = 6.303. For f, P < 0.0001, F = 12.92, ****P < 0.0001. For g, P = 0.0128, F = 4.639. For h, P = 0.0069, F = 5.403. For j and l, Brown-Forsythe and Welch ANOVA; n = 6. For j, P = 0.0325, F* = 4.173. For l, P = 0.0012, F* = 6.083. P values reported for statistically different groups; all other groups, NS.