Figure 3.

Submerged normal human bronchial epithelial (NHBE) cells were stimulated with indicated concentrations of SCFAs for 24 h. A, Cell lysates were harvested for RNA extraction to analyse t-PA mRNA expression by RT-PCR (n = 4-8); B, Submerged NHBE cells were stimulated with 10 mmol/L acetic acid, 10 mmol/L propionic acid, 1 mmol/L butyric acid, 10 mmol/L valeric acid and 10 mmol/L hexanoic acid. Supernatants were collected after 48 h of stimulation to analyse t-PA protein by ELISA (n = 6); C, Submerged NHBE cells were stimulated with 10 mmol/L propionic acid for 48 h. Then t-PA activity in the supernatants was measured by chromogenic activity kit (n = 5-6); D, NHBE cells were harvested from transwells after stimulation with 10 mmol/L of propionic acid for 48 h. Whole cell lysates and apical and basolateral medium were collected. Levels of t-PA in the cell lysates and medium were measured by ELISA (n = 8). Data shown are mean ± SEM of 4 independent experiments. * P < .05, **P < .01, ***P < .001, ****P < .0001 when compared to non-stimulated cells