Senescent human hepatocytes express a unique secretory phenotype and promote macrophage migration

Figure 1 Stress-induced senescence in human hepatocytes. A: HepG2 cells were treated with the indicated doses of hydrogen peroxide (H₂O₂) and survival assessed using a tetrazolium reduction assay; B: Phase contrast, Ki67 immunocytochemistry, β-galactosidase activity, p21 immunocytochemistry, and heterochromatin protein 1 beta (HP1β) immunocytochemistry in control (Con.) and H₂O₂-treated senescent (Sen.) HepG2 7 d after release from H₂O₂ treatment. All panels magnification × 200, except HP-1β magnification × 630; C: Quantification of p21⁺ nuclei; D: Quantification of cells with HP1β⁺ foci. Data are representative of at least 3 independent experiments. ^bP < 0.01 vs control group.