Previous data in our lab has shown that high concentration (200 μM) H2O2 exposure induces iron dysregulation in muscle cells. It is known that following strenuous exercise, oxidative stress is induced in tissues, leading to iron dysregulation, and generation of reactive oxygen species. Due to the unstable nature of H2O2 in solution and the critical role of the liver in iron homeostasis, we sought to see how human hepatocytes would respond to a 12-hour low-dose H2O2 exposure that mimics the concentration of neutrophils during the inflammatory response using glucose oxidase (GOX) and Catalase (CAT) PURPOSE: To determine the effects of a low-concentration, H2O2 exposure on the iron regulatory proteins such as TfR, and Ferritin Light-Chain (FLC) in HepG2 cells. METHODS: When HepG2 cells reached 80% confluency, iron treatments of 10, 50, and 100 μM were imposed for 24 hours using an FeCl3 solution diluted in media. Groups that received both iron and H2O2 treatments were exposed to 12 hours of iron, followed by 12-hour incubation with media that included both iron and a GOX-CAT cocktail. Western blots were carried out to measure protein content relative to controls. Cell viability was assessed using an MTT assay. RESULTS: MTT assays for both FeCl3, and FeCl3 + H2O2 groups did not show any significant cell death. Treatment with FeCl3 alone resulted in a significant decrease in TfR for all three groups when compared against controls (C=1±0.1 SEM vs. 0.71±.1; p<0.01; n=12). We observed a significant increase in FTL, but only in the 10 μM group (C=1± 0.1 vs. 1.6±0.2; p<0.01; n=11). We saw no significant change in FTL at 50 and 100 μM. H2O2 treatments driven by GOX and CAT produced concentrations of 5-10 μM, mimicking neutrophils during inflammatory response. The addition of a low concentration H2O2 stress resulted in a 9-fold increase of FTL content at all iron exposure concentrations (C=1±0.3 vs 9.3 ±0.9 10 μM; p<0.01; n=4). Groups of 50 and 100 μM also showed similar results, with an increasing trend. CONCLUSION: A low concentration exposure of H2O2 and iron to human hepatocytes results in a significant increase in FTL when compared to iron exposure alone. This suggests that liver cells have a robust defense against iron-dysregulation induced by oxidative stress. We are still evaluating changes that occur in other iron regulatory proteins.