Fig. 4.

Modulation of HIF-1α and Nrf2 half-life by As(III). HepG2 cells were cultured under normoxia for 24 h. At 24 h, the medium was changed and the cells were treated with 50 μM As(III) under normoxia (16 % O₂) or hypoxia (5 % O₂) for 4 h. After 4 h, cells were treated with cycloheximide (CHX, 10 μg/ml) for the indicated times. a The HIF-1α levels in the As(III)-treated controls were set to 1. Values represent mean ± SEM of three independent experiments. b, c Representative Western Blots. One hundred micrograms of isolated total protein was subjected to Western blot analysis with an antibody against HIF-1α or α-tubulin. d The Nrf2 levels in the As(III)-treated controls were set to 1. Values represent mean ± SEM of three independent experiments. e, f Representative Western Blots. One hundred micrograms of isolated total protein was subjected to Western blot analysis with an antibody against Nrf2 or α-tubulin