Fig. 3

Role of IL-33 in brain endothelial adhesion molecule expression and blood–brain barrier (BBB) integrity changes. Four hours after i.c.v. LPS injection, the mRNA levels of adhesion molecules in WT and IL-33^−/− mouse brains were measured by qRT-PCR. The mRNA levels of VCAM-1 (a), ICAM-1 (b), P-selectin (c), and E-selectin (d) were decreased in IL-33^−/− mice. The VCAM-1, P-selectin, and E-selectin protein levels, as measured by western blotting, were significantly decreased at 4-h i.c.v. LPS treatment in IL-33^−/− mice compared to WT mice (e). Western blot analysis of brain albumin levels was performed to examine BBB integrity between WT and IL-33^−/− mice after 4-h LPS i.c.v. injection (f). At 24 h after LPS injection, western blot analysis of VCAM-1, P-selectin, E-selectin, and albumin expression (g) revealed that VCAM-1, P-selectin, and E-selectin were all decreased, but no change in albumin level was observed in IL-33^−/− as compared to WT mice (g). n = 4 mice per group; *P < 0.05, **P < 0.01, and ***P < 0.001