FIG. 1.

H. somnus 8025 induces endothelial cell apoptosis in a dose- and time-dependent manner. (A) Bovine pulmonary artery endothelial cells (5 × 10⁴) were incubated at 37°C with 5% CO₂ for 6 h at various MOI. (B) Bovine pulmonary artery endothelial cells (5 × 10⁴) were incubated with H. somnus 8025 organisms at an MOI of 10:1 for 2 to 24 h at 37°C with 5% CO₂. Untreated (UT) and staurosporine (200 nM)-treated (Stauro) cells were included as negative and positive controls, respectively. Apoptosis was detected using Hoechst 33342 staining as described previously. These data illustrate the mean ± SEM of three separate experiments. Statistical analysis was performed by ANOVA followed by the Tukey-Kramer significant difference test (∗, P < 0.05).