Figure 3.

Intestinal iron absorption, gene and protein expression, and serum iron levels in suckling and weaned Tmprss6 knockout mice. Tissues were taken from 15-day-old Tmprss6 knockout mice or wild-type littermate controls, or from 25- to 28-day-old Tmprss6 knockout mice or wild-type littermate controls that had been weaned onto an iron-deficient diet at 21 days of age. Tissues also were taken from 25- to 28-day-old wild-type littermate controls weaned onto a control diet. (A) Relative hepatic Hamp1 mRNA expression is shown and (B) serum hepcidin1 concentration is shown. (C) The absorption of a test dose of ⁵⁹Fe was measured in separate cohorts of similarly treated mice and the proportion of the test dose absorbed is shown. (D) The level of ferroportin protein in isolated duodenal enterocytes and (E) serum iron concentration also were determined. Gene expression levels were calculated relative to the housekeeping gene Hprt and are expressed as a proportion of the values of 25- to 28-day-old wild-type littermates on the control diet. Ferroportin protein expression levels were calculated relative to β-actin and are expressed as a proportion of wild-type littermates at each time point. (D) A representative blot is shown. The number of mice analyzed in each group is indicated in parentheses under each bar. The data represent means ± SEM. (A, B, C, and E) Bars with the same letter are not statistically different from each other. (D) *P < .005. 15d, 15 days old; Fpn, ferroportin; Tmprss6 KO, Tmprss6 knockout mice; Tmprss6 KO-D, Tmprss6 knockout mice on an iron deficient diet; 25-28d, 25–28 days old; WT, wild-type littermates; WT-C, wild-type littermates on a control diet; WT-D, wild-type littermates on an iron-deficient diet.