Figure 7. Regulation of PlGF secretion in the RPE/choroid. In general, placental growth factor (PlGF) secretion increased during cultivation. The inhibition of nuclear factor-kappa B (NF-κB) displayed a significant influence on PlGF secretion on the apical side (A) and on the basal side (B) at 24 h and at 48 h. The inhibition of SP-1 significantly reduced vascular endothelial growth factor (VEGF)-A secretion on the apical side after 48 h (C) and on the basal side at 24 h and at 48 h (D). The reduction of PlGF after p38 inhibition did not reach significance on the apical side (E) but did on the basal side after 48 h (F). The inhibition of VEGFR-2 did not significantly reduce PlGF at the apical side (G) but displayed significant effects on the basal side after 24 h and 48 h (H). Supernatants were collected for 24 h and were analyzed in enzyme-linked immunosorbent assay (ELISA). Significance was determined with the Student t test; + p<0.01, ++ p<0.01 +++=p<0.001. n=3 (A, B, E, F, G), n=6 (C, D), n=4 (H). Bars depict the mean and the standard deviation.