The authors demonstrated that IL-1α and IL-1β stimulated non-CF human bronchial epithelial (HBE) cells to upregulate and secrete both MUC5B and MUC5AC in a dose-dependent manner, an effect that was neutralized by the inhibition of the IL-1α/IL-1β receptor (IL-1R1).
Total airway mucins were elevated in CF compared to non-CF BALF irrespective of infection, and higher densities of mucus flakes containing mucin 5B and mucin 5AC were observed in samples from CF patients.
Here, we identified a novel connection between CFTR/ENaC expression and the intracellular Zn<sup>2+</sup> concentration in the regulation of MUC5AC, a major secreted mucin that is highly expressed in CF airway.
We investigated the length polymorphisms in the central repetitive regions of MUC1, MUC2, and MUC5AC by Southern blot and tested for association with MI in CF subjects.
A significant association was found between the overall distribution of MUC5AC VNTR length and CF lung disease severity (p = 0.025; n = 468 patients); plus, there was robust association of the specific 6.4 kb HinfI VNTR fragment with severity of lung disease (p = 6.2×10(-4) after Bonferroni correction).
In addition, while the number of goblet cells expressing MUC5AC was similar in CF and non-CF regenerated epithelia, the number of MUC5B-immunopositive goblet cells was lower in CF grafts.
Alterations in antibacterial peptide function, as well as the increased mucin expression and secretion (MUC 5AC and MUC 5B), are important biochemical factors responsible for the propensity for infection in CF airways.
We compared expression levels of three mucin genes, MUC1, MUC2, and MUC5/5AC, known to be expressed in the respiratory tract of CF, allergic rhinitis, and normal individuals.