Dietary iron enhanced colonic inflammatory cytokine release and Stat3 signaling during acute colonic inflammation.

<p>Colonic IL-6 (A), IL-11 (B) and IL-1β (C) release from colonic tissue explants were measured after 24 hours in culture at 37°C. The tissue explants were harvested Iron and Control (Ctrl) mice treated with or without DSS for 7 days. Colonic Stat3 phosphorylation (D) was also determined in Iron/DSS and Ctrl/DSS mice compared with non-DSS treated mice at day 7. Immunofluorescent staining (E) of F4/80 (green) and IL-6 (red; left panels) or phosphorylated Stat3 (red; right panels) at day 3 of DSS treatment identified F4/80⁺ macrophages (arrows) as a main source of IL-6 production and epithelial crypt cells as active sites of nuclear pStat3 localization (white arrowheads) in Iron and Ctrl mice. Results are expressed as mean±SEM, n = 3–8. * <i>P</i><0.001 denotes significance between DSS treatment versus no treatment; # <i>P</i><0.05 denotes significance between Iron/DSS versus Ctrl/DSS or Iron versus Ctrl mice. Scale bar denotes 25 µm.