Fig 2: Effect of IL-17A-neutralizing mAb on neuron loss in peri-infarct region of mice with ischemic stroke. (A) The representative immunofluorescent staining results showed the effect of IL-17A-neutralizing mAb on NeuN positive numbers in peri-infarct region of mice following 1-h MCAO/R 3 days’ treatment (scale bar = 100 μm). (B) Statistical analysis results demonstrate that the i.c.v. injection of IL-17A-neutralizing mAb (2.0 μg) could significantly inhibit the NeuN positive cell loss when compared with that of 1-h MCAO/R 3 days + IgG isotype group. Data are presented as mean ± SEM; ***p < 0.001 vs. sham group; ##p < 0.01 vs. 1-h MCAO/R 3 days + IgG isotype group (n = 6 per group).

Fig 3: Effects of IL-17A neutralizing mAb on the neurological outcome of mice with ischemic stroke. The statistical analysis results of neurological score (A), longa score (B), corner test (C), beam balance test (D), and rotarod test (E) showed that neutralization of IL-17A could significantly improve the neurological functions of mice following 1 h MCAO/R 7 d when compared with that of IgG isotype group (n = 10 per group). Data were presented as mean ± SEM, and the statistical analysis was performed by using one-way ANOVA followed by Bonferroni test. **P < 0.01, ***P < 0.001 vs. corresponding Sham group; ##P < 0.01, ###P < 0.001 vs. corresponding IgG isotype group.

Fig 4: IL-17A-neutralizing mAb alleviated the neural cell apoptosis in the peri-infarct region of mice with ischemic stroke through caspase-12-dependent pathway. The representative and quantitative analysis results of Western blot showed that the i.c.v. injection of IL-17A-neutralizing mAb (2.0 μg) could significantly inhibit the cleavage levels of caspase-3 (A) and caspase-12 (D) in the peri-infarct region of mice following 1-h MCAO/R 24 h. In addition, the injection of IL-17A-neutralizing mAb could significantly increase Bcl-2 expression levels (E), but decrease the expression levels of Bax (F) in the peri-infarct region of mice with ischemic stroke. However, the injection of IL-17A-neutralizing mAb did not affect the cleavage levels of caspase-8 (B) and caspase-9 (C) in the peri-infarct region of mice after 1-h MCAO/R 24-h treatment. Data are presented as mean ± SEM; *p < 0.05, **p < 0.01, ***p < 0.001 vs. sham group; #p < 0.05, ##p < 0.01 vs. 1-h MCAO/R 24 h + IgG isotype group (n = 6 per group).

Fig 5: Interleukin-17A (IL-17A)–neutralizing monoclonal antibody (mAb) improved the neurological outcome of mice with ischemic stroke. (A) The diagram of experimental design showed that the intracerebroventricular injection of IL-17A-neutralizing mAb (2 μg, i.c.v) or IgG isotype within 3-h reperfusion after 1-h MCAO treatment. At 24 h of reperfusion, the mice were sacrificed for Western blot and triphenyl tetrazolium chloride (TTC) staining. At 3 days of reperfusion, the mice were used to evaluate the neurological function and then sacrificed for immunofluorescent staining. (B) At 24 h of reperfusion after 1-h MCAO, the infarct size of IL-17A-neutralizing mAb group was significantly smaller than the IgG isotype group. (C) Bar graph showed the statistical analysis results of infarct size among three groups (n = 6 per group). Data are presented as mean ± SEM; ***p < 0.001 vs. sham group; ###p < 0.001 vs. 1-h MCAO/R 24 h + IgG isotype group. In addition, the IL-17A-neutralizing mAb could significantly improve the neurological function that included neurological score (D), the latency to fall of wire hanging (E), the Longa score (F), and the laterality index of corner test (G) of mice following 1 MCAO/R 3 days (n = 10 per group). Data are presented as quartile; ***p < 0.001 vs. sham group; ##p < 0.01, ###p < 0.001 vs. 1-h MCAO/R 24 h + IgG isotype group.