Figure 4
From: Novel tricyclic pyrrolo-quinolines as pharmacological correctors of the mutant CFTR chloride channel
Characterization of PP028 corrector. (A) Dose–response relationship for PP028 as F508del-CFTR corrector in the absence (top) and presence (bottom) of VX-809 (1 µM). Data (mean ± SD) were obtained with the HS-YFP data on CFBE41o- cells. Dotted and dashed lines indicate average activity of vehicle and VX-809, respectively. Data are fitted with a Hill function. Values of EC50 and rate (Hill coefficient) are shown. (B) Top: detection of F508del-CFTR (C and B bands) and GAPDH in cell lysates by immunoblot. CFBE41o- cells were treated with vehicle, VX-809 (1 µM), and PP008 or PP028 (10 µM), plus/minus VX-809. Bottom: densitometric analysis of F508del-CFTR protein maturation. Data report band C/band B ratio, following normalization for GAPDH. ***, p < 0.001; vs. vehicle. ###, p < 0.001 vs. VX-809 (ANOVA with Tukey’s post-hoc test). (C) Representative short-circuit current recordings (left) and summary of data (right) from experiments on bronchial epithelia from F508del/F508del patients. Epithelia were treated for 24 h with vehicle, 1 µM VX-809, 10 µM PP028, or VX-809 plus PP028. Short-circuit current was recorded during sequential addition of amiloride (10 µM), CPT-cAMP (100 µM), VX-770 (1 µM), CFTRinh-172 (inh-172, 10 µM), UTP (100 µM), CaCCinh-A01 (inh-A01, 50 µM). The scatter dot plot shows the amplitude of CFTRinh-172 effect. ***, p < 0.001 vs. control. ###, p < 0.001 vs. VX-809 (Kruskal–Wallis non parametric test).
