Fig. 5

Hemoglobin treatment induces iron deposition and reduces Iba1 expression. The primary microglia derived from WT mice were treated with SFHb for 2 h as indicated concentration. Distribution of Iba1 (green) and iron localization (black) was shown in microglia by double staining. The cells highlighted within the dashed box were demonstrated at a higher magnification in the enlargement. The asterisk (*) indicates that Iba1 signals were absent at the Perls’ iron-positive area (a). The bar graph shows the significant changes in the size of microglia that are Perls’ iron-positive. SFHb treatment greatly increases microglial size, which is dose-dependent (b). The SFHb-treated microglial cells have a larger area of positive Perls’ iron staining, suggesting SFHb-induced iron deposition inside microglia (c). The linear-regression graph illustrates that Perls’ iron-positive signals are negatively related to Iba1-positive signals, n ≥ 50 cells (d). Scale bar, 50 μm. Values represent means ± SEM. Significant differences between the groups are expressed as follows: *P < 0.05; ***P < 0.001, one-way ANOVA followed by Newman-Keuls multiple comparison tests. The experiment was repeated three times and in n ≥ 150 cells