Fig. 4: MAPK13-dependent PHGDH pS371 sensitizes hepatocytes to oxidative stress-induced cell death.

a, b Primary hepatocytes isolated from Phgdh^LKO mice were transfected with Flag-Phgdh WT, Flag-Phgdh S371A or Flag-Phgdh S371D. Cells were treated with 10 μM CQ for 24 h (a). Transfected cells were treated with 0.5 mM H₂O₂ for 24 h. Cells were stained with 1 μg/mL PI and 10 μg/mL Hoechst, and the percentage of dead cells was quantified (b). c, d SK-Hep1 cells stably expressing shPHGDH were infected with lentivirus expressing shNT or shMAPK13 and then infected with lentivirus expressing Flag-rPHGDH WT or Flag-rPHGDH S371D respectively. Cells then were treated with 20 μM CQ for 24 h (c). Infected cells were treated with 0.5 mM H₂O₂ for 24 h. Cell viability was determined using trypan blue staining (d). e, f Primary hepatocytes isolated from Phgdh^LKO mice were transfected with siNC or siMapk13 and then transfected with Flag-Phgdh WT or Flag-Phgdh S371D. Cells were treated with 10 μM CQ for 24 h (e). Transfected cells were treated with 0.5 mM H₂O₂ for 24 h. Cells were then stained with 1 μg/mL PI and 10 μg/mL Hoechst, and the percentage of dead cells was quantified (f). Immunoblots are representative of three independent experiments. Data represent the means ± SD of three independent experiments. P values were determined by two-tailed Student’s t-test.