Costimulation of Murine Osteoblasts with Interferon-γ and Tumor Necrosis Factor-α Induces Apoptosis through Downregulation of Bcl-2 and Release of Cytochrome c from Mitochondria

Figure 1

Effects of IFNγ and TNFα on the growth of MC3T3-E1 mouse osteoblasts. Exponentially growing MC3T3-E1 mouse osteoblasts were seeded in 96-well plates, incubated for 24 h, and treated for 72 h with various concentrations of IFNγ (a), TNFα (b), or both (c). Cell viability was determined, and the percentage of cytotoxicity is shown above the symbols. Data represent the mean ± SEM of three independent experiments. The exponentially growing MC3T3-E1 mouse osteoblasts were also seeded in 3 cm dishes, incubated for 24 h, stimulated with or without 10 ng/ml IFNγ and/or 5 ng/ml TNFα, and analyzed at various time points (d), with time 0 indicating the addition of cytokines. Viable cells were counted using a hemocytometer. Data represent the mean ± SEM of three independent experiments. versus untreated cultures by Student’s -test.

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