A Translocated Bacterial Protein Protects Vascular Endothelial Cells from Apoptosis
Figure 1
Bh BepA Meditates Inhibition of Apoptosis in ECs
(A and B) HUVECs were infected for 24 h with the indicated Bh strains (MOI = 300) or left uninfected for this period (control). If not indicated differently, apoptosis was then triggered by the addition of actinomycin D. Then, 12 h later, (A) morphological changes were visualized by recording phase contrast images (bar = 40 μm), and (B) caspase-3/-7 activities were determined with a specific fluorogenic peptide substrate. Arrowheads (A) indicate apoptotic cells displaying membrane blebbing.
(C) Twenty-four hours after induction of apoptosis, the loss of membrane asymmetry was quantified by flow cytometric analysis of AlexaFluor488 Annexin V– and PI-stained cells, allowing us to quantify the rate of apoptotic cells (Annexin V–positive and PI-negative). Mean and standard deviation (SD) are shown for one representative out of three independent replica experiments. All strains were tested a minimum of three times in triplicate samples.