IO induces significant hepatic inflammation in vivo. C57BL/6 mice (N = 6) were fed a purified diet with no added iron and subjected to i.p. injection of 20 mg/kg (IA) or 200 mg/kg (IO) dextran-iron twice per week. Mice were sacrificed, and liver tissues were harvested at various time points. (A) Prussian blue staining shows heavy iron accumulation. Original magnification ×400. (B) RNA and (C) protein levels of various inflammatory factors were determined. (D) Immunofluorescence analysis showed upregulation of TNF-α and IL-1β expression. Original magnification ×200. (E-F) Expression of HNF4α at the mRNA and protein levels (E) and expression of miR-122 in the pri- and mature forms (F) were determined. Data were normalized to the IA group and are presented as mean ± SEM. *P < .05; **P < .01; ***P < .001 vs IA.