Cell surface expression of ferroportin in BMDMs. (A) In untreated BMDMs, endogenous ferroportin (green) and CD11b/Mac1 (red) fluorescence labeling were analyzed using confocal microscopy. Arrows in panel Ai show the vesicular staining of ferroportin alone, whereas arrows in panels Aii-x illustrate the cell surface staining of ferroportin and its partial colocalization with the cell surface marker CD11b. (Ai-ii) XY sections; (Aiii-x) XZ sections. (B) In iron-treated BMDMs, endogenous ferroportin (green, Bi-ii,v-ix) and CD11b/Mac1 (red, Biii) fluorescence labeling were analyzed using confocal microscopy. Serial XY (Bi) and XZ (Bv-ix) sections clearly show the strong plasma membrane localization of ferroportin in iron-overloaded cells. Panel Biv corresponds to the merge of panels Bii and Biii and shows colocalization of ferroportin with CD11b/Mac1.