Fig. 3

RRM2 upregulates GSH by sustaining GSS. a The ferroptosis-related metabolic axis from glucose to GSH. b–g The levels of glycine (b), glutamate (c), cysteine (d), cystathionine (e), serine (f) and glucose (g) were measured in HepG2 and SMMC-7721 cells with or without ectopically expression or knocked down of RRM2. h, i mRNA levels of CBS, CTH, SHMT2, GSS and GPX4 were analyzed by qPCR in HepG2 (h) and SMMC-7721 cells (i) administered the indicated treatment. j, k Protein levels of CBS, CTH, SHMT2, GSS and GPX4 were analyzed by immunoblotting in HepG2 and SMMC-7721 cells (j). The level of RRM2 was normalized to that of GAPDH, and the normalized level of RRM2 in the untreated group was arbitrarily set to 100% (k). (l) GSH levels were measured in WT and GSS^−/− HepG2 and SMMC-7721 cells with or without RRM2 overexpression or knockdown, as indicated. The data are shown as the mean ± SD from three biological replicates. **P < 0.01 indicates statistical significance. Data from b−i and k−l were analyzed using one-way ANOVA