Fig. 1: Serum changes the sensitivity of cells to ferroptosis.

Cell viability of MEFs cultured with 10% FBS-1 to FBS-12 and treated with different doses of RSL3 (A) or ERS2 (B) for 24 h. Cell viability of MEFs cultured in Rcm or Scm and treated with different doses of RSL3 (C) or ERS2 (D) with or without liproxstatin-1 (Lip-1, 1 μM) for 24 h. Rcm, R-FBS complete medium; Scm, S-FBS complete medium. Lipid peroxidation level of MEFs that were treated with 2 μM RSL3 for 2 h (E), 2 μM ERS2 for 4 h (F) with or without Lip-1 (1 μM) for 2 h before staining with 2.5 μM BODIPY-C11 (C11). G Scheme for the procedure of MEFs originally cultured in Rcm or Scm and then switched to Scm or Rcm for 24 h, followed by treatment with RSL3/ERS2 dissolved in the original Rcm or Scm medium, and cell viability was assessed after 24 h. R-Scm, MEFs culture medium changed from Rcm to Scm; S-Rcm, MEFs cultured medium changed from Scm to Rcm. Cell viability of MEFs treated with different doses of RSL3 (H) or ERS2 (I) dissolved in original medium for 24 h according to the procedure shown in Fig. 1G. J Lipid peroxidation level of MEFs cultured in indicated medium for 12 h or 24 h and treated with 2 μM RSL3 with or without Lip-1(1 μM) for 2 h before staining with 2.5 μM C11. Data are presented as mean ± s.d., n = 3 independent repeats. Unpaired, two-tailed t-test; ****P < 0.0001. NS not significant.