Figure 1. Anoxia induces the expression of mRNA and production of MUC5AC in NHNE cells.

(A) MTT assay to determine cytotoxic effects of anoxia. Cell viability was not significantly affected by less than 6 h of anoxia (n = 3, *p<0.05, †p<0.0001). (B) The expression of the MUC5AC gene according to anoxia stimulation (95% N₂/5% CO₂ atmosphere in the hypoxic chamber) for 0–24 h in NHNE cells. MUC5AC gene expression was increased under anoxic conditions, measured by RT-PCR. (C) The expression of MUC5AC mRNA was maximally induced at 12 h during anoxia (measured by real-time PCR, n = 3, *p<0.05, **p<0.001). d) Mucus secretion was sampled at 2, 6, 12, and 24 h after incubating of NHNE cells under anoxic conditions and measured in dot blots with anti-MUC5AC antibody. Secreted MUC5AC was highest at 12 h under anoxic conditions (n = 3, **P<0.001). Data is shown as mean ± standard deviation.