Fig. 4

SEM reveals expanded surface area and loosely packed mucus in IES. NHBE ALI cultures after 3 weeks of BMGLS application and processing for SEM. (A) Cntrl sample with (i) pseudostratified morphology and apical cilia. (ii) Mucin bundles and (iii) close-up view of MUC5AC covering MUC5B entangled polymers. (B) HCS sample with densely packed mucus (inset) and (ii) apical cilia. (C.i) IES with apical orifice and loosely packed mucus (inset) at 0.3% BMGLS application and (ii) secreted mucin bundles. (D.i) 0.6% BMGLS induces enlarged IES comprising mucus within tubular-like structures. (ii) Apical mucin bundles and (iii) orifice from apical point of view. Scale bars, all 10 μm