Endothelial activation in response to LPS treatment and to tumor cell challenge. BALB/c mice were treated with LPS or injected with 5 × 105 4T1-GFP tumor cells (green) intravenously. SCID mice were injected with 5 × 105 1205Lu-GFP tumor cells (green) intravenously. Lungs were harvested at the indicated times and analyzed by immunohistochemistry for the presence of different antigens of endothelial activation. (A) Representative images, acquired with a confocal microscope, of stainings for E-selectin, VCAM-1, and VAP-1 are shown (Alexa Fluor 633, red). (B) Dynamics of endothelial activation upon LPS treatment. Time zero represents untreated mice and indicates the basal expression levels of the adhesion molecules. Data represent mean ± SD, n = 3 mice. Representative images are shown in supplemental Figure 1. E-selectin (C), VCAM-1 (D), and VAP-1 (E) induction upon challenge with 4T1-GFP tumor cells was evaluated as described in the “Microscopy and image analysis” subsection of “Methods”. In (C-E) n ≥3 mice and data represent (C) mean ± SD or (D-E) mean ± SEM. In (C) values corresponding to the time points 15 minutes, 24 hours, and 72 hours are zero. Scale bars represent 50 µm.
