Figure 8

LPS treatment does not affect EP4 receptor expression and EP4 receptor activation restores LPS- induced disruption of HMVEC-L barrier function. HMVEC-L were treated with either LPS (1 µg/ml) or vehicle for (a) 4 and (b) 6 hours. (c,d) For assessment of barrier function HMVEC-L were starved for 1 hour and treated with LPS (1 µg/ml) or vehicle (arrowhead) for 6 hours. At this time point, an EP4 receptor-agonist ONO AE1 329 (30 nM) was added (arrow). To detect differences in barrier function (measured as change in resistance), Δ% values were calculated. The black lines mark the time points which were used to calculate Δ% increase shown in (d). (a) Data show the percentage of EP4 receptor mRNA as percent of vehicle control; (b): Data show the percentage of EP4 receptor protein as percent of vehicle control; (c): Data show mean normalized resistance + SEMs; (d): Δ% increase was calculated by subtracting normalized resistance of the first time point marked in c from the second time point, and multiplying the value with 100. Statistical analysis was performed using one sample t-test against 100 for (a–b) and one-way ANOVA followed by Bonferroni’s post hoc test for (d); n = 5–10; ***p < 0.001.