Fig. 3

a Effects of cell type and dextran size on macromolecular permeability. A serosa to lumen gradient of 1.25 μM 4 or 10 kDa dextran was imposed on TYP, ISC, ENT, GOB, and PAN organoids for 30 min. i Representative images clearly depict the higher dextran accumulation in TYP, ENT, and GOB organoids. ii Levels of net fluorescence in all organoids were then analyzed as described in the text and normalized to that in 4 kDa TYP organoids (=1.0). (n = 4 for ISCs, ENTs, GOBs, and PANs, and n = 2 for TYPs, for both 4 and 10 kDa). Using two-way ANOVA, the serosal to luminal flux of both dextran levels was higher in ENT and GOB organoids, and 10 kDa dextran permeability was lower. b Effects of AT1002 (an active fragment of ZO toxin) and larazotide on permeability to 4 kDa dextran. ENT and ISC organoids were incubated overnight in 10 μg/mL AT1002 (+Z) or 12.5 mM larazotide acetate (+L) or both (Z + L) and then permeability to 4 kDa dextran was determined (i). Using two-way ANOVA, the dextran flux was higher in ENTs and greatest in AT1002-treated organoids (ii). (For ENTs, n = 3 each for CONs, +Z, +L, and n = 2 for + Z + L; for ISCs, n = 3 for CONs, and n = 2 for + Z, +L and + Z + L). Supporting data sets are deposited in the figshare repository [50]. CON control cell, ENT enterocyte, FITC fluorescein isothiocyanate, GOB goblet cell, ISC intestinal stem cell, PAN Paneth cell, TYP typical