Fig. 5.

Treatment with H₂O₂ increased the numbers of apoptotic cells and this increase was augmented in cells expressing dominant-negative mutants that impair hemichannels. CEF cells were infected with high-titer RCAS(A) retroviral vehicle (V) or recombinant RCAS(A) retroviruses containing Cx50, and Cx50 mutants E48K, P88S or H156N, or Cx50 WT and mutants in in combination. Cells were treated with 1 mM H₂O₂ for 10 h, and analyzed by using the Dead Cell Apoptosis Kit with FITC–Annexin V and PI (Molecular Probes). At least five microphotographs of fluorescence fields were taken under a 10× microscope (Olympus) under phase-contrast or with FITC or Rhodamine filters. Positive cells were quantified by counting and are shown as a percentage. The data are presented as the mean±s.e.m. (n=3). ***P<0.001. Scale bar: 50 μm.