FPN1 mRNA and protein levels increase transiently after erythrophagocytosis (EP) by J774 macrophages. J774 cells (approximately 1 × 106) were incubated in the presence of 15 × 106 opsonized human erythrocytes (EIgG) for 1.5 hours. Noningested erythrocytes were lysed and removed, and incubation continued for the times indicated. (A) Northern analysis of FPN1. Results are from a single experiment using human erythrocytes and were similar to data from experiments using sheep erythrocytes (n = 2) and rat erythrocytes (n = 2). (B) Western blot analysis of FPN1. Results shown are representative of 2 independent experiments performed using human erythrocytes. (C) FPN1 mRNA levels normalized to β-actin (♦), and protein levels of the 65-kDa FPN1 band (▪) plotted as a function of time after EP.
