FIGURE 3.

PIEZO1 mediates ionizing radiation-induced pulmonary endothelial cell ferroptosis by increasing intracellular calcium concentration and calpain activity. (A) Intracellular Ca²⁺ measured using Fluo4-AM (5 mM) across groups. Histograms showing differences in Ca²⁺ concentrations across groups. (B) Calpain activity assay in HULEC-5a cell pre-treated with Yoda1 (2.5 µM) or GsMTx4 (5 µM) for 24 h before ionizing radiation (IR). (C) Lipid peroxidation assessment in HULEC-5a cells pre-treated with PD151746 (20 µM) for 24 h before IR. (D) ROS measurement in HULEC-5a cell pre-treated with PD151746 (20 µM) for 24 h before IR or without radiation. (E) Lipid peroxidation assessment in HULEC-5a cells pre-treated with PD151746 (20 µM) and/or Yoda1 for 24 h. The Lipid peroxidation level of the control group is the same result shown in Figure 3C. The grouping experiment belongs to single batch of experiment. (F) ROS measurement in HULEC-5a cells pre-treated with PD151746 (20 µM) and/or Yoda1 for 24 h. (G) Western blotting analysis of ACSL4, SLC7A11, DMT1, and GPX4 expression in HULEC-5a cell pretreated with PD151746 (20 µM) for 24 h followed by IR and/or treatment with Yoda1. Data were plotted as means ± SEM. n = 3 independent repeats. **, p < 0.01 vs control. ^&&, p < 0.01 vs PD151746. ^##, p < 0.01 vs GsMTx4. ^$$, p < 0.01 vs Yoda1; ^%%, p < 0.01 vs IR.