Fig. S6.

Responses of capillary or lymphatic endothelium to addition of the proinflammatory cytokine, TNF-α, into the lumen of the upper epithelial channel. Schematics (Top) and immunofluorescence confocal microscopic views (Bottom) show the organ-level tissue–tissue interface of intestinal villus epithelium and capillary endothelium (A) or lymphatic lacteal endothelium (B) cultured within the two adjacent microchannels in the gut-on-a-chip. Immunofluorescence staining for ICAM-1 revealed that epithelial stimulation with TNF-α (50 ng/mL) for 12 h induced endothelial activation and up-regulated expression of this surface adhesion receptor (red), which displayed a bright, uniform pattern of staining on the surface of the capillary endothelium (A, Right Bottom) and a more diffuse and punctate pattern on the lymphatic endothelium (B, Right Bottom). (Scale bar, 50 µm.) (C) Quantitation of the expression level of ICAM-1 on each endothelium (*P < 0.001; n = 50).