FIG. 2.

HCV infection stabilizes HIF-1α through cellular kinase pathways. (A) Uninfected Huh-7 cells and HCV-infected Huh-7 cells were treated with DMSO (lane2), PI3-kinase inhibitor LY294002 at 50 μM for 12 h (lane 3), Src kinase inhibitor SU6656 at 10 μM for 2 h (lane 4), or p38 MAP kinase inhibitor SB203580 at 10 μM for 15 h (lane 5). Whole-cell lysates were prepared and subjected to Western blot assays with anti-HIF-1α antibody. Actin is the protein loading control, and core is used as a representative HCV protein expressed in infected cells. (B) Uninfected and HCV-infected Huh-7 cells were treated with DMSO (lane 2) or p42/44 MAP kinase inhibitor PD98059 at 50 μM (lane 3) for 6 h. Whole-cell lysates were prepared and subjected to Western blot assays with anti-HIF-1α antibody. (C) HCV activates HIF-1α through the STAT-3 and NF-κB pathways. Uninfected and HCV-infected Huh-7 cells were transiently transfected with empty vector plasmid (lane 2), STAT-3 dominant-negative mutant Tyr705 to Phe (lane 3), STAT-3 dominant-negative mutant Ser727 to Ala (lane 4), and IκBα dominant-negative mutants Tyr 42 to Phe (lane 5), Tyr 305 to Phe (lane 6), and Ser 32,36 to Ala (lane 7). Whole-cell lysates were prepared and subjected to Western blot analysis with anti-HIF-1α antibody. Actin is the protein loading control, and core is a representative HCV protein expressed in infected cells.