FIG. 1.

IL-1β and TNF-α increase retinal endothelial cell permeability. A–D: BRECs were grown to confluence on transwell filters and then exposed to IL-1β or TNF-α in a concentration- and time-dependent manner. The monolayer permeability to 70 kDa dextran was measured as described in research design and methods. A: Cells were treated with 1, 10, and 100 ng/ml IL-1β for 24 h. B: Cells were treated with 10 ng/ml IL-1β for 0.5, 6, and 24 h. C: Cells were treated with 1, 2.5, 5, and 10 ng/ml TNF-α for 6 h. D: Cells were treated with 5 ng/ml TNF-α for 0.5, 6, and 24 h. E and F: IL-1β and TNF-α effect on cell viability. BRECs were treated with 10 ng/ml IL-1β or 5 ng/ml TNF-α for 6 and 24 h. E: Relative cell viability was measured by calcein AM cleavage by live cells. F: Retinal endothelial cell apoptosis was evaluated by caspase-3/7 activation. As a positive control of apoptosis induction, cells were treated with 100 nmol/l staurosporine (STP) for 6 h. The results represent the mean ± SEM of at least four independent experiments and are expressed relative to control (Ctrl). **P < 0.01, significantly different from control as determined by ANOVA followed by Dunnett post hoc test.