ATP Induces Disruption of Tight Junction Proteins via IL-1 Beta-Dependent MMP-9 Activation of Human Blood-Brain Barrier In Vitro

Figure 6

BzATP-induced tight junction disruption and endothelial coculture system hyperpermeability were attenuated by MMP inhibition. (a) The levels of IL-1β were not significantly altered in MMP-9-treated groups versus control groups (). No statistically significant differences were found between IL-1RA + MMP-9 groups and MMP-9 groups in the levels of IL-1β (). (b) Exposure to MMP-9 significantly increased the permeability to FITC-dextran compared with the control group (). However, IL-1RA failed to attenuate MMP-9-induced paracellular hyperpermeability (). (c) Immunofluorescence staining showed that the expression of ZO-1 and occludin in MMP-9 groups was significantly decreased compared with controls, while IL-1RA + MMP-9 groups showed no improvement in the levels of the two tight junction proteins.