Figure 1.

Erastin (Era) promotes increased levels of ROS-induced lipid peroxides and Propranolol (Prop), through the generation of hydrogen sulfide (H₂S), is able to revert it. (A) The levels of intracellular ROS (DCF-DA) decrease upon Prop exposure, and Era, although increasing the ROS levels, when co-administrated with Prop the levels are similar to the control, at 6 and 16h. (B) The levels of mitochondrial ROS, assessed by MitoSox, are not affected by the presence of Era and/or Prop, at 6 and 16h. (C) Era induces lipid peroxides (C11-Bodipy) generation and although Prop alone did not affect the lipid peroxides content, its combination with Era reverts the levels generated by Era, being this effect more prominent at 16h. (D) The levels of GSH (total and LT:free total) decrease upon exposure to Era and/or Prop for 16h. (E) The variation of the extracellular levels of cysteine (Cys) indicate that Era inhibits the uptake of Cys by HUVECs, while Prop does not interfere with this process. (F–H) Show the regulation of transcriptional expression of genes encoding, respectively, prostaglandin-endoperoxide synthase 2 (PTGS2), glutathione peroxidase 4 (GPX4) and glutathione synthetase (GSS). Erastin decreases significantly GPX4 and PTGS2 expression and tend to decrease GSS expression, being this effect rescued by propranolol. (I) Era does not affect HUVECs death (annexin V plus PI positive cells) while 16h of Prop exposure, with and without Era, increases the ratio of HUVECs death. (J) Era does not affect H₂S levels of HUVECs while Prop increases, at 16h. In graphs the dashed line represents the control condition. All data are normalized to the control condition and represented as mean ± SD. *p<0.5, **p<0.01, ***p<0.001, ****p<0.0001.