Fig. 4.

Effect of sulfasalazine on heme-oxygenase 1 (HO-1) expression and the effect of silencing HO-1 on sFlt-1 secretion ± sulfasalazine.

Sulfasalazine upregulates heme-oxygenase 1 (HO-1) a) mRNA expression and b) protein production in endothelial cells. Furthermore it upregulates HO-1 c) mRNA expression and d) protein production in cytotrophoblasts cells. There is also an increase in HO-1 e) protein expression in preterm preeclamptic placental explants treated with sulfasalazine. Silencing HO-1 gene in cytotrophoblasts cells did not affect f) sFlt-1 secretion and sulfasalazine continued to reduce sFlt-1 secretion from cytotrophoblasts in the presence of HO-1 silencing. Data are means ± SEM of three independent experiments. p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001. (Kruskal-Wallis).