Fig. 1.

Vitamin K1 inhibits ferroptosis in vitro. a Murine NIH3T3 cells were pretreated at 37 °C for 30 min in the absence or presence of increasing (indicated) concentrations of vitamin K1 (vit.K1). Ferroptosis was induced thereafter for 24 h by the addition of 5 µM RSL3 or 2.5 µM erastin, respectively. b Human HT-1080 cells were pretreated at 37 °C for 30 min in the absence or presence of increasing (indicated) concentrations of vitamin K1. Ferroptosis was induced thereafter for 24 h by the addition of 5 µM RSL3 or 25 µM erastin, respectively. Cell death was quantified by FACS analysis using 7-amino-actinomycin D (7-AAD) and phosphatidylserine accessibility (Annexin V staining) as markers. Each graph shows the mean ± SD of three independent experiments. c NIH3T3 cells were pretreated at 37 °C for 30 min in the presence or absence of 1 µM ferrostatin-1 (Fer-1) or 10 µM vitamin K1, as indicated. Ferroptosis was induced thereafter for 24 h by addition of 5 µM RSL3 or 2.5 µM erastin. Equal amounts of protein (20 µg/lane) were resolved by SDS-PAGE, and expression of ACSL4 was detected by western blotting. The blot was stripped and re-probed with an antibody against GPX4 and thereafter β-actin as a loading control