Fig. 8.

Co-administration of C4 and C18 rescues the channel function of CFTR mutants. CFBE41o- cell lines stably expressing the E92K, L1077P, or M1101K constructs were maintained at 37°C or 27°C for 24 h and then treated with C4, C18, C4+C18, or lumacaftor (each 5 µM, for 16 h). The short-circuit current (Isc) responses (all measured at 37°C) from cells bearing CFTR constructs (A) E92K, (B) L1077P, or (C) M1101K are shown. Data are expressed as the CFTR_inh172-sensitive Isc (ΔIsc), calculated by subtracting the Isc after CFTR_inh172 treatment from the peak forskolin/genistein-stimulated Isc. Smooth (left) bars are associated with 37°C incubation, and dotted (right) bars with 27°C. Statistical significance is presented as: ^ns no significant difference, *P < 0.05, **P < 0.01, ***P<0.001 (n = 4–12 for each condition) compared to control conditions (37°C, n = 4–12 and 27°C, n = 4–5). Amiloride (100 µM) was present during the whole experiment to avoid interference by ENaC-mediated Na⁺ currents.