Fig 1: The IL-33/ST2 axis mediates the disruption of the BBB model by Sly hemolytic products. (A) TEER method to detect the role of IL-33/ST2 signaling in the process of BBB disruption by Sly hemolytic products. (B) MMP-9 mediates the suppression of Claudin-5 expression by IL-33. AMPM, p38 inhibitor Adezmapimod (SB203580). MMST, MMP-9 inhibitor, Marimastat (BB-2516). (C) Relative protein expression of Claudin-5. (D and E) The p38 signaling pathway mediates the promotion of IL-6 and IL-8 expression by IL-33. The data are presented as the mean ± standard deviation (SD) and were analyzed by one-way ANOVA. **P < 0.01, *P < 0.05.
Fig 2: The IL-33/ST2 axis mediates the invasion of SS2 into the mouse BBB. (A) Intravenous injection of IL-33 increases the permeability of EB molecules in the mouse brain (n = 5). (B) Intravenous injection of anti-ST2 delays the death of the acute inflammatory mouse model caused by SS2 infection (n = 10). (C) Intravenous injection of anti-ST2 reduces the permeability of EB in the brains of SS2-infected mice (n = 5). (D) Intravenous injection of anti-ST2 reduces the bacterial load in the brains of SS2-infected mice. (E) Intravenous injection of anti-ST2 has no effect on the bacterial load in the blood of SS2-infected mice. The data are presented as the mean ± standard deviation (SD) and were analyzed by one-way ANOVA (A–C) or Student’s t test (D and E). **P < 0.01, *P < 0.05.
Fig 3: IL-33 originating from Sly hemolysin products can increase the permeability of the BBB model. (A) Intravenous injection of Sly increases the concentration of IL-33 in mouse serum. (B) Sly lysis of RBC releases a substantial amount of IL-33. (C) Knockout of the sly gene reduces the SS2-induced increase in IL-33 release. (D) TEER measurement method to assess the impact of IL-33 on the permeability of the BBB model (n = 3). (E) HRP permeability experiment to evaluate the effect of IL-33 on the permeability of the BBB model. The data are presented as the mean ± standard deviation (SD) and were analyzed by one-way ANOVA. **P < 0.01, *P < 0.05.
Fig 4: IL-33 Inhibits the expression of tight junction proteins in BMEC and enhances activation of the p38 signaling pathway. (A) IL-33 suppresses the expression of Claudin-5 and can cause abnormal distribution of Claudin-5. (B) Relative protein expression of Claudin-5. (C) Immunofluorescence analysis method is used to examine the expression and distribution of Claudin-5 in hCMEC/D3 due to IL-33. The working concentration of IL-33 is 10 ng/mL. Bar, 10 µM. (D) IL-33 promotes the expression of MMP-9 and phosphorylation of p38 in hCMEC/D3. (E) Grayscale analysis of the expression of MMP-9. (F) Grayscale analysis of the expression of p38, and phosphorylated p38. (G) MMP-9 expression in cells treatment with IL-33 was measured using ELISA (n = 3). The data are presented as the mean ± standard deviation (SD) and were analyzed by one-way ANOVA. **P < 0.01, *P < 0.05.
Supplier Page from Abcam for Recombinant Mouse IL-33 protein (His tag N-Terminus)