Figure 2.

iNOS-induced mtDNA release activates the cGAS-STING pathway. (A-B) The expression of cGAS and STING in cells transfected with iNOS, n = 6. (C) The ONNO levels were measured to reflect nitrative stress, n = 6. (D) The mRNA expression levels of IFN-β were measured, n = 6. (E) iNOS expression increased the cytosolic mtDNA content in cardiomyocytes, n = 6. (F-H) mtDNA depletion blunted the effects of iNOS on increasing cGAS-STING and IFN-β expression, n = 6. (I-K) mtDNA increased cGAS-STING and IFN-β (N) expression in isolated cardiomyocytes. Data are presented as the mean ± SEM. Statistical analysis was performed using a 1 or 2-way ANOVA with a Tukey's multiple-comparison post-hoc test comparisons between multiple groups. iNOS. inducible NO synthase; SNAP, S-Nitroso-N-acetyl-DL-penicillamine; EtBr, ethidium bromide; IFN-β, interferon-β. *, P < 0.05. **, P < 0.01.***, P < 0.001. ****, P < 0.0001.