A high glucose condition sensitizes human hepatocytes to hydrogen peroxide-induced cell death

Abstract

Oxidative stress is known to play a key role in the progression of liver disease, including non-alcoholic steatohepatitis (NASH), which is often accompanied by hyperglycemia. This study examined the influence of high glucose on oxidative stress-induced hepatic cell death. Hc cells, a normal human hepatocyte-derived cell line, were cultured in normal-to-high glucose (5.5-22 mM)-containing medium with varying concentrations (0.01-1 mM) of hydrogen peroxide. In certain experiments, cyclosporine A (CyA), which inhibits the mitochondrial permeability transition (MPT) pore, or Z-VAD-FMK (z-VAD), a pan-caspase inhibitor, were added to the medium. Cell viability was evaluated using a colorimetric assay. The mode of cell death was determined by nuclear staining methods using Hoechst 33258 and Sytox green. Neither high glucose (22 mM) nor 0.05-0.5 mM of hydrogen peroxide alone killed Hc cells. However, a combination of the two induced cell death, causing the nuclei of Hc cells to become expanded rather than condensed, and the nuclear membrane to become weak. CyA, but not z-VAD, blocked cell death. These results suggest that a high glucose condition may cause human hepatocytes to undergo hydrogen peroxide-induced necrotic cell death.