Ferritin L (FTL) and Ferritin H (FTH) subunits are responsible for intercellular iron storage. We previously reported increasing amounts of liver cytoplasmic and nuclear iron content during acute phase response (APR). Aim of the present study is to demonstrate intracellular localization of ferritin subunits in liver compared with extra hepatic organs of rat under physiological and acute phase conditions. Rats were administered turpentine-oil (TO) intramuscularly to induce a sterile abscess (acute-phase-model) and sacrificed at different time points. Immunohistochemistry was performed utilizing horse-reddish-peroxidise conjugated secondary antibody on 4μm thick section. Liver cytoplasmic and nuclear protein were used for Western blot analysis. By means of immunohistology, FTL was detected in cytoplasm while a strong nuclear positivity for FTH was evident in the liver. Similarly, in heart, spleen and brain FTL was detected mainly in the cytoplasm while FTH demonstrated intense nuclear and a weak cytoplasmic expression. Western blot analysis of cytoplasmic and nuclear fractions from liver, heart, spleen and brain further confirmed mainly cytoplasmic expression of FTL in contrast to the nuclear and cytoplasmic expression of FTH. The data presented demonstrate the differential localization of FTL and FTH within hepatic and extra hepatic organs being FTL predominantly in the cytoplasm while FTH predominantly in nucleus.
Keywords: Ferritin; acute phase; iron regulation; liver; nuclear localization.