Inhibition of CFTR-mediated intestinal chloride secretion by nornidulin: Cellular mechanisms and anti-secretory efficacy in human intestinal epithelial cells and human colonoids
Fig 4
Mechanisms of CFTR inhibition by nornidulin in T84 cells.
(A) A representative trace of apical chloride current (ICl-) is shown. CFTR was first stimulated with 20 μM genistein, followed by the addition of nornidulin at various concentrations to the apical side (n = 5). (B–E) Examine how upstream regulatory proteins affect nornidulin’s inhibition of CFTR-mediated apical chloride current (ICl-). T84 cells were pre-treated with specific activators or inhibitors: CPT-cAMP (100 μM) for PKA, IBMX (100 μM) for PDE, NaF plus Na3VO4 (1 mM) for PP, and Compound C (50 μM) for AMPK. After pre-treatment, dose-inhibition studies with nornidulin were performed, with each experiment repeated five times (n = 5). (F) Compiles dose-response curves from all the dose-inhibition studies. The data are fitted to Hill’s equation and presented as means of percentage of agonist-stimulated apical chloride current (ICl-), with standard error of the mean (S.E.M.) indicated (n = 5).