Fig. 6. Vascular endothelium mediates the radiation damage.

a DIC microscopic views showing the villus morphology of the human Caco-2 intestinal epithelium cultured with and without human vascular endothelium under control conditions (Con) or after radiation exposure (Rad) (bar, 50 μm). b Quantification of villus heights measured under the conditions described in a (n = 3; ^**P < 0.01; n.s. not significant). c Representative immunofluorescence confocal micrographs of the Gut Chip device with the villus intestinal epithelium stained for epithelial tight junctions, ZO-1 (red) and intestinal mucin protein, MUC2 (green) (blue, DAPI-stained nuclei; bar, 50 μm). d Quantification of fluorescence intensities (a.u.) of MUC2 normalized per cell number under the conditions shown in c (n = 3; ^**P < 0.01, ^***P < 0.001; n.s. not significant)