Fig. 1

Identification of CLD in mouse intestine (a, b) or Caco-2-cells (c, d). a, b) Oil red O staining of CLD in the proximal intestine of mice produced (a) in vivo after an acute lipid gavage showing their absence in the fasted state (T0) and their abundance at 1 h (T1) or 4 h (T4) and (b)) in vitro after 1 h incubation of isolated intestinal loop with luminal mixed micelles. E: enterocytes, LP: lamina propria, c) Visualisation of CLD accumulation in differentiated Caco-2 cells fixed at 10 min after apical addition of mixed micelles, using Bodipy 494/503 (Bo) or LD540 (LD), in either a transverse plane (x/y) or the corresponding Z projection. The nuclei were stained with DAPI and the tight junction constituent ZO-1 was immunolabeled. Ap: apical and Ba: basolateral poles. Bars: 10 μM. d) Live imaging of Caco-2 cells, performed in the presence of LD540 in the medium and apical loading of mixed micelles, showing no CLD at T = 0 min but their accumulation in the basement of living Caco-2 cells at T = 10 min after apical addition of mixed micelles. Both LD fluorescence and light transmission (light) are shown to visualize cell edges, in x/y planes. The results are representative of three (a, b) or two (c, d) separate experiments