Growth differentiation factor 15 alters intestinal barrier and increases permeability: A new molecular target in inflammatory bowel disease

Figure 3 In vitro assessment of the effects of growth differentiation factor 15 on intestinal barrier permeability. Colonic organoids were treated with fluorescein isothiocyanate-dextran 4k (FD4), and the relative FD4 intensity (ratio between the mean gray value inside the colonic organoid and the sum of the mean gray values inside and outside) was calculated for each organoid. A: Untreated colonic organoid (healthy control), relative FD4 intensity = 0.092; B: Growth differentiation factor 15-treated organoid (100 ng/mL), relative FD4 intensity = 0.163. Scale bar: 100 μm; C: Relative FD4 intensity in organoid lines under different conditions, presented using a Tukey’s box plot. Images were obtained with a Leica SP5 confocal microscope using a 10 × objective and analyzed in ImageJ. For each organoid line, ≥ 10 organoids from three different wells (≥ 30 total organoids) were analyzed per condition. ^aP < 0.05 and ^bP < 0.01, one-tailed paired t-test. GDF: Growth differentiation factor; FD4: Fluorescein isothiocyanate-dextran 4k; IFNg: Interferon gamma.