Figure 5.

IL-6 could be involved in host defense in AD and DS brain. ELISA based analysis of IL-6 in serum samples showing increased levels in AD and highest level in DS when compared with hepcidin (p < 0.0001; A). Samples were analyzed from AD and age matched older controls (OC), IL-6 levels were significantly higher in AD serum (B; p < 0.0001). Ferritin (FTH) was present close to a SP in DS brain analyzed by double immunofluorescence, and did not co-localize with Aβ42 positive plaques (C). Another control brain section from white matter tract (WMT) of corpus callosum (CC), labeled with hepcidin, expression being visible in the WMT (in the oligodendrocytes), whereas IL-1β being present in the microglia with minimal co-localization (D–F). Brain sections from AD (HP, hippocampus) and DS (SFG) when stained with hepcidin and IL-1β, revealed similarly the presence of hepcidin (punctuate, vesicular appearance) in the hippocampal neurons, whereas IL-1β was visible only in the microglia with minimum co-localization (G,H). When control and DS brain sections of HP and SFG were stained for hepcidin and IL-6, there was less IL-6 visible in the control brain (I), whereas there was a higher co-localization seen in the granule cells of hippocampus of DS subjects (J–L). Scale bar: (C and G) = 20 μm, (D–F) = 50 μm, (H–L) = 25 μm. ***p < 0.001, ****p < 0.0001.