Fig 2: Upregulation of CFTR improved autophagic flux by increasing the protein expression of cathepsin B and cathepsin D. (a) The representative images of western blotting for the expression of LAMP1, CTSD, and CTSB in HUVECs. HUVECs were pretreated with Forskolin and Baf1 (20 nM) for 45 min and then treated with PA for an additional 24 h followed by western blot. (b) The analysis of western blot. *Versus BSA group; #versus PA group; &versus PA+FOR group, p < 0.05, n = 6. (c) The representative images of western blotting for the expression of CTSD and CTSB in HUVECs with CFTR knockdown. HUVECs were transfected with negative control siRNA or CFTR siRNA for 48 h and then treated with PA for an additional 24 h followed by western blot. (d, e) Analysis results of western blot. *p < 0.05, n = 10.

Fig 3: Protein expression of pSGLT1, SGLT1, villin, total protein content, PepT1 as well as CFTR in Caco-2, HT29-MTX and co-cultured Caco-2 and HT29-MTX cells.pSGLT1 and SGLT1 were blotted on the same membrane, which was stripped after incubation with the pSGLT1-antibody. Each lane on each membrane represents a biological replicate, experiments were performed in triplicates.

Fig 4: Densitometrical analysis of Western blots performed with pSGLT1, SLT1, villin, PepT1 and CFTR in relation to total protein content in Caco-2, HT29-MTX and co-cultured Caco-2 and HT29-MTX cells.Values shown are the mean ± SD of three independent experiments. * p < 0.05; ** p < 0.01.

Fig 5: Cellular arrangement (cross sections) of jejunum organoids grown in 2D on Snapwells® for 18 days.Immunohistochemical staining (including isotype controls) of CFTR was performed. Red triangles indicate cells with a positive signal of CFTR. Representative figures are shown, chosen from three independent experiments with three technical replicates per staining.