TGF-β mediated accumulation of ROS associates with increased NADPH oxidase activity. (A) During the TGF-β dependent transdifferentiation of M1-4HSCs, ROS levels increase after 48 and 72 hours. (B) M-HTs show a reduction of ROS levels to about 50% as compared to untreated M1-4HSCs. (C) DPI inhibits TGF-β caused ROS accumulation in M1-4HSCs. (D) TGF-β treatment of M1-4HSCs induces NADPH oxidase activity after 48 hours. M-HTs display vast NADPH oxidase activity. For all situations, n = 3. * p < 0.05.