Regulation of Human MUC7 Mucin Gene Expression by Cigarette Smoke Extract or Cigarette Smoke and Pseudomonas aeruginosa Lipopolysaccharide in Human Airway Epithelial Cells and in MUC7 Transgenic Mice

Fig. (1) Effect of CSE, LPS and CSE/LPS on mucin gene transcription in vitro, using human NCI-H292 cells. Total RNA was isolated from the control cells and treated cells and reversed transcribed. MUC7 expression (panel A) and MUC5AC expression (panel B) was determined by quantitative Real-Time PCR (qRT-PCR). The level of different mucin mRNA was normalized to GAPDH. Each bar represents the SD from three independent experiments. * indicates p < 0.05. LPS, lipopolysaccharide from P. aeruginosa, used at concentration of 10 µg/ml in all experiments (an optimal dose, determined by the dose-response curve; data not shown). CSE, cigarette smoke extract, used at several different concentrations, either alone or in combination with LPS, as indicated. Relative levels of mucin mRNA are expressed as fold of induction comparing to the control, untreated cells, set arbitrary at a value of 1.