Deficiency in PKCα downregulates Fpn expression in physiology and diabetes. (A) Serum iron and Fpn expression in the (B) duodenum and (C) spleen were determined in 16-week-old female and male PKCα^−/− vs WT mice. Immunoblotting for PKCα shows the successful deletion of PKCα in PKCα^−/− mice. (D) Representative confocal images show the localization of Fpn in the duodenum of WT and PKCα^−/− male mice. Arrow, membrane Fpn expression; arrowhead, intracellular Fpn. (E) Serum iron and Fpn expression in the (F) duodenum and (G) spleen were determined in WT and PKCα^−/− male mice with and without STZ-induced diabetes. (H) Serum iron was determined in female and male db/db and db/db;PKCα^−/− mice. Liver iron content was determined in db/db and db/db;PKCα^−/− mice by (I) biochemical assay and (J) Perls iron staining. Fpn protein expression was determined in the (K) duodenum and (L) spleen of db/db and db/db;PKCα^−/− female mice. (M) Confocal images showing Fpn (red) localization in the enterocytes of db/db and db/db;PKCα^−/− mice, with F-actin staining (green) as a marker of the cytoskeleton. Data are shown as mean ± SEM (n = 5-10). ∗∗P < .05 and ∗P < .01 compared with their WT controls. ^#P < .01 comparing the percentages of differences between WT and PKC^−/− mice. ^&P < .01 compared with the WT control (WT-Cont) group. Bars, 50 μm.