FIG 6.

Role of IL-6. Pericytes were mock infected (Mock CM) or infected with JEV (MOI, 20; JEV CM) for 48 h. The supernatants were collected and mixed with an equal volume of fresh medium. Brain microvascular endothelial cells were exposed to the manipulated media (Mock CM and JEV CM) or treated with IL-6 (20 ng/ml) in the absence or presence of AG490 (50 μM) for 24 h. One set of manipulated medium (JEV CM) was modified by neutralization with IL-6 neutralizing antibody (10 μg/ml) for 30 min before being subjected to exposure. Untreated cells were used as the control. (A) Cellular proteins were isolated and subjected to fluorogenic assay for the determinations of trypsin-like (left graph) and chemotrypsin-like (right graph) proteasome activity. n = 4. (B) Total cellular proteins were isolated and subjected to Western blotting with antibodies against ZO-1 and β-tubulin. One representative blot of four independent experiments is shown. The content in control was defined as 100%. (C) The TEER (left graph) and transendothelial permeability to dextran-FITC (right graph) were measured. n = 4. **, P < 0.01 versus medium control; ##, P < 0.01 versus JEV CM; &&, P < 0.01 versus IL-6 control.