Hepatic overexpression of Hfe does not exacerbate the systemic iron deficiency caused by homozygous loss of Tmprss6. (A-E) Analyses of TS, tissue iron concentrations, and hepatic hepcidin mRNA expression in 8-week-old female Hfe^−/− mice harboring 0, 1, or 2 mutant Tmprss6 alleles that are also either null or hemizygous for a liver-specific Hfe transgene. Graphed are mean values obtained from analyses of TS (A), LIC (B), heart nonheme iron concentration (C), hepcidin mRNA expression relative to β-actin (Actb) expression (D), and spleen nonheme iron concentration (E). In panel A, 8 Hfe^−/−Tmprss6^+/+, 8 Hfe^−/−Tmprss6^+/−, 6 Hfe^−/−Tmprss6^−/−, 6 Hfe^−/−Tmprss6^+/+Hfe tg, 8 Hfe^−/−Tmprss6^+/−Hfe tg, and 8 Hfe^−/−Tmprss6^−/−Hfe tg mice were analyzed. In panels B, C, and E, 8 Hfe^−/−Tmprss6^+/+, 9 Hfe^−/−Tmprss6^+/−, 7 Hfe^−/−Tmprss6^−/−, 8 Hfe^−/−Tmprss6^+/+Hfe tg, 9 Hfe^−/−Tmprss6^+/−Hfe tg, and 8 Hfe^−/−Tmprss6^−/−Hfe tg mice were analyzed. In panel D, 7 Hfe^−/−Tmprss6^+/+, 7 Hfe^−/−Tmprss6^+/−, 6 Hfe^−/−Tmprss6^−/−, 6 Hfe^−/−Tmprss6^+/+Hfe tg, 8 Hfe^−/−Tmprss6^+/−Hfe tg, and 8 Hfe^−/−Tmprss6^−/−Hfe tg mice were analyzed. Error bars represent SD. Hfe tg indicates Hfe transgene. *P < .005 compared with Hfe^−/−Tmprss6^+/+; †P < .05 compared with Hfe^−/−Tmprss6^−/−; ‡P value not significant compared with Hfe^−/−Tmprss6^−/−; §P < .05 compared with Hfe^−/−Tmprss6^+/+Hfe tg; ‖P < .005 compared with Hfe^−/−Tmprss6^+/+Hfe tg, and ¶P < .05 compared with Hfe^−/−Tmprss6^+/+ mice.