The tPA-EGFP organelle and type-2 organelle are the same. (A) Representative confocal images of the Golgi region of transfected cells expressing tPA-EGFP (Ai; EGFP fluorescence green in color-merged panel) or nontransfected cells labeled for endogenous tPA immunoreactivity (Aii; green in color-merged panel, cells were exposed to 3mM Na butyrate, 24 hours to up-regulate endogenous tPA expression levels13) and counterstained with a specific antibody to TGN46 (red in color-merged panels). (B) Cells stained for endogenous GRO-α (i), MCP-1 (ii), IL-8 (iii), or eotaxin-3 (iv) immunoreactivity (red in color-merged images) in cells expressing tPA-EGFP (EGFP fluorescence green in color-merged images). Regions indicated by the white boxes are shown in grayscale to the right of each image. Cells were pretreated with IL-1β (GRO-α, MCP-1, and IL-8) or IL-4 (eotaxin-3) as described in “Stimulation protocols and ELISAs.” (C) IL-8 (red and top panels in grayscale images), GRO-α (green and middle panels in grayscale images), and VWF (blue and bottom panels in grayscale images) immunoreactivity in an IL-1β-pretreated cell. The white boxes indicate regions shown in grayscale to the right of the color image.