Figure 4.

Prolonged HGF treatment improves functional rescue of Phe508del-CFTR by the VX-809/VX-770 combination without stimulating proliferation of polarized CFBE cells. (a) Variation in TEER of polarized CFBE-Phe508del cells treated for 15 days with DMSO, HGF (50 ng/ml), VX-809 (3 μM), VX-770 (0.5 μM) alone or in the indicated combinations. Conditions leading to significant or near-significant TEER variations are indicated. (b) WB analysis of whole cell lysates from polarized CFBE-Phe508del cells treated as in (a). Shown are representative images of CFTR and Ki-67 immunoblots together with bar plots of band intensity quantification, normalized to DMSO (means ± SEM) from three independent assays. Tubulin was used as a loading normalizer in band intensity quantification. (c) Fluorescence decay curves of iodide influx assays in polarized CFBE-Phe508del/HS-YFP cells treated as in (a) and stimulated with 5 μM Fsk alone or together with 20 μM of Gen in the presence or absence of 25 μM of inh172, as indicated. Fluorescence (F) was plotted over time as percentage of fluorescence at time 0 (F₀). (d) Iodide influx rates calculated as in Fig. 1b. Data are means ± SEM of three independent assays. ^*p < 0.05, ^&p < 0.005, and ^#p < 0.001.