HIFs temper hypoxic production of mROS to inhibit macrophage necroptosis. (A) Cell death as measured by Zombie Aqua positivity of BMDMs from mice with myeloid-specific deletion of Hif1 (mHIF1^−/−), Hif2 (mHIF2^−/−), both Hif1 and Hif2 (mHIF1/2^−/−), or controls cultured under normoxia (21% O₂) or hypoxia (1% O₂). n = 3 sets of cells/group. Data are representative of three independent experiments. *, P < 0.05 by one-way ANOVA followed by Tukey’s test. (B) Levels of mROS as measured by MitoSOX in BMDMs cultured under normoxia, hypoxia, or hypoxia with MitoTEMPO (MT). (C) Cell death of MitoTEMPO-treated BMDMs cultured under hypoxia. For B and C, n = 3 sets of cells/group and are representative of two independent experiments. *, P < 0.05; **, P < 0.01 by one-way ANOVA followed by Tukey’s test. (D) Necroptosis gene expression in BMDMs cultured under normoxia or hypoxia. n = 3 sets of cells/group. Data represent two independent experiments. *, P < 0.05; **, P < 0.01; ***, P < 0.001 by one-way ANOVA followed by Tukey’s test. (E) Cell death of vehicle (Veh)– or necrostatin-1 (Nec-1)–treated BMDMs cultured under hypoxia. n = 3 sets of cells/group. Data represent two independent experiments. ***, P < 0.001 by one-way ANOVA followed by Tukey’s test. (F) Survival of mice treated with vehicle or necrostatin-1 after MI. n = 3–8 mice/group pooled from two independent experiments. *, P < 0.05 by log-rank (Mantel–Cox) test. (G) Percent infarct/LV, percent AAR/LV, percent infarct/AAR measured 7 d after MI in mice treated with vehicle or necrostatin-1. n = 3–5 mice/group pooled from two independent experiments. *, P < 0.05; **, P < 0.01; ***, P < 0.001 by one-way ANOVA followed by Tukey’s test. All data are presented as mean ± SEM.