Pixel positivity was determined by the number of pixels representing stained tissue divided by the total number of pixels in the whole liver section. Cluster of differentiation 45–positive (CD45+) GSK-3 signaling pathway staining was performed on methanol/acetone (1:1) fixed liver cryosections using a rat anti-CD45 antibody (Ly-5, 1:150; BD Pharmingen, San Diego, CA) and detected with goat antirat Alexa Fluor 594 or goat antirat Alexa Fluor 488 (1:200; Invitrogen, Mulgrave, Victoria, Australia) and mounted with Long Gold antifade reagent, containing 4′,6-diamidino-2-phenylindole (DAPI; Invitrogen), for nuclear quantitation. Quantification was performed

by the acquisition of six random, nonoverlapping fields of view per tissue sample, followed by colocalization analysis of CD45 and DAPI (nuclear quantification) using the AnalySIS Life Science Professional

program (Olympus, Melbourne, Victoria, Australia). Ferritin staining was performed ALK inhibitor using a rabbit antiferritin antibody (1:800; Dako, Glostrup, Denmark) and detected using a goat antirabbit Alexa Fluor 594 (1:200; Invitrogen). Plasma alanine aminotransferase (ALT) was measured as an indicator of liver injury using a kit according to the manufacturer’s instructions (Sigma-Aldrich, St. Louis, MO). Liver F2-isoprostanes, a marker of LPO, was measured by gas chromatography/mass spectrometry using a deuterium-labeled Palbociclib price internal standard, as previously described.27 The antioxidant, butylated hydroxyl toluene, was added to liver tissue to scavenge any ROS generated during tissue storage and processing. Activities of antioxidant enzymes copper/zinc and manganese SOD were measured in the liver as an index of oxidative stress using a kit according to the manufacturer’s instructions (Cayman Chemical, Sydney, New South Wales, Australia). Liver hydroxyproline content was measured as a biochemical marker of liver collagen using a kit according to the manufacturer’s instructions (QuickZyme

Biosciences, Leiden, Netherlands). Results are expressed as mean ± standard error of the mean (SEM), where n = 5-15 mice per group. Differences between groups were analyzed using analysis of variance with Tukey’s multiple comparison post-test or an unpaired Student’s t test (GraphPad Prism; GraphPad Software, Inc., La Jolla, CA). Differences between groups were defined as statistically significant for P < 0.05. Expression of Hfe, Tfr1, Tfr2, Bmp6, Id1, and Hamp1 genes is shown in Table 1. Hfe expression in Tfr2mut and WT mice was similar and undetectable in Hfe−/− and Hfe−/−×Tfr2mut mice (P < 0.001). Tfr2 mRNA expression in Tfr2mut and Hfe−/− ×Tfr2mut mice was decreased by approximately 65%, compared with non-iron-loaded WT mice (P < 0.001). Tfr2 mRNA expression in Hfe−/− and iron-loaded WT mice was also lower than non-iron-loaded WT mice (P < 0.05).