Fig. 5.

SAM derived from serine metabolism modulates macrophage polarization. qPCR analysis of M1 (a) or M2 markers (b) in WT BMDMs starved of SG for 12 h; supplemented with the indicated concentration of formate, GSH, or SAM; and then treated with IFN-γ for 12 h (a) or IL-4 for 24 h (b). qPCR analysis of M1 and M2 markers in PHGDH-WT and PHGDH-KO BMDMs supplemented with or without 400 μM serine (c, d) or 400 μM SAM (e, f) for 12 h and then treated with IFN-γ for 12 h or IL-4 for 24 h. g–j Western blot analysis with the indicated antibodies. PHGDH-WT and PHGDH-KO BMDMs supplemented with or without 400 μM SAM for 12 h were treated with IFN-γ for 12 h (g) or IL-4 for 24 h (i). WT BMDMs starved of SG for 12 h and supplemented with 400 μM SAM were treated with IFN-γ for 12 h (h) or IL-4 for 24 h (j). The data are from three independent experiments with biological duplicates in each and are shown as the mean ± SEM values (n = 3) (a–f) or are representative of three independent experiments (g–j). NS not significant (p ≥ 0.05); *p < 0.05; **p < 0.01; ***p < 0.001