FIG. 3.

Normal and malignant HSCs demonstrate differences in the regulation and management of the antioxidant system. Normal HSCs express higher levels of primary antioxidant enzymes SOD and CAT. Malignant HSCs are subject to elevated levels of ROS produced by NOX enzyme and rely on higher cellular concentrations of GSH as well as the GSH metabolic system to manage the malignant HSC redox state. CAT, catalase; GPx, glutathione peroxidase; GR, glutathione reductase; GSH, reduced glutathione; GSSG, oxidized glutathione; H₂O₂, hydrogen peroxide; NADPH, nicotinamide adenine dinucleotide phosphate; NOX, nicotinamide adenine dinucleotide phosphate oxidase; SOD, superoxide dismutase. To see this illustration in color, the reader is referred to the web version of this article at www.liebertpub.com/ars