Fig. 6

Heme induces ferroptosis in human nucleus pulposus cells. a–c Viability of HNPCs was measured by CCK-8 after treatment with heme (a), FAC (b), and erastin (c) at concentrations of 0, 5, 10, 20, 40, 60, 80, and 100 μg/mL for 24 h. The data were analyzed with GraphPad Prism 5.02 software. d–f The protein levels of GPX4, Bcl-2, and Bax in HNPCs treated with heme (d), FAC (e), and erastin (f) at concentrations of 0, 5, 10, and 20 μg/mL for 24 h. g Viability of HNPCs was measured by CCK-8 after 20 μg/mL heme treatment for 24 h with or without 30 μg/mL DFO pretreatment for 1 h (upper), and the protein levels of GPX4 in HNPCs were measured after 20 μg/mL heme treatment for 24 h with or without 30 μg/mL DFO pretreatment for 1 h (lower). h Identification of ROS and ferroptosis-related metabolites in HNPCs after treatment with 20 μg/mL heme, 20 μg/mL FAC, and 10 μg/mL erastin for 24 h using high-resolution MALDI-TOF MS. i ROS levels in HNPCs after 20 μg/mL heme treatment for 24 h with or without 30 μg/mL DFO pretreatment for 1 h. The data were analyzed with GraphPad Prism 5.02 software. *P < 0.05, **P < 0.01