Response to iron overload in cultured hepatocytes

Abstract

AbstractIron is essential for a variety of physiological processes. Hepatic iron overload acts as a trigger for the progression of hepatic steatosis to nonalcoholic steatohepatitis and hepatocellular carcinoma. In the present study, we aimed to study the effects of iron overload on cellular responses in hepatocytes. Rat primary hepatocytes (RPH), mouse primary hepatocytes (MPH), HepG2 human hepatoma cells and Hepa1-6 mouse hepatoma cells were treated with FeCl3. Treatment with FeCl3 effectively increased iron accumulation in primary hepatocytes. Expression levels of molecules involved in cellular signaling such as AMPK pathway, TGF-β family pathway, and MAP kinase pathway were decreased by FeCl3 treatment in RPH. Cell viability in response to FeCl3 treatment was decreased in RPH but not in HepG2 and Hepa1-6 cells. Treatment with FeCl3 also decreased expression level of LC-3B, a marker of autophagy in RPH but not in liver-derived cell lines. Ultrastructural observations revealed that cell death resembling ferroptosis and necrosis was induced upon FeCl3 treatment in RPH. The expression level of genes involved in iron transport varied among different liver-derived cells- iron is thought to be efficiently incorporated as free Fe2+ in primary hepatocytes, whereas transferrin-iron is the main route for iron uptake in HepG2 cells. The present study reveals specific cellular responses in different liver-derived cells as a consequence of iron overload.