Ang-1 induces expression of IL-8 mRNA and protein. (A) A representative IL-8 Northern blot. HUVECs were serum starved for 12 hours and were then stimulated with Ang-1 (300 ng/mL) and collected 1, 2, 3, and 6 hours later. C indicates control samples, 18S refers to rRNA. (B) Means (± SEM; n = 3) of IL-8 mRNA intensity triggered by 300 ng/mL of Ang-1. (C) Means (± SEM; n = 3) of IL-8 mRNA intensity measured after 1 hour of Ang-1 addition. (D) Means (± SEM; n = 6) of IL-8 protein (detected with ELISA) in culture medium in response to Ang-1, Ang-2, and Ang-4 (300 ng/mL) and VEGF (80 ng/mL). (E) Means (± SEM; n = 6) of IL-8 protein measured after 12 hours of Ang-1 (100%) or Ang-1 plus rhTie2-FC protein (100× in excess of Ang-1) or Ang-1 plus cycloheximide (50 μg/mL, CHX). For panels C and D, *P < .05 compared with control values. For panel E, *P < .05 compared with Ang-1 alone.