Fig. 1

IL-1 cytokine expression is decreased at pathological pH. Representative immunoblot analysis of IL-1β and IL-18 at three different pH levels (7.4, 6.8 and 6.5) (a). Densitometric analysis corresponds to the active forms of IL-1β (15 kDa, b) and IL-18 (18 kDa, c). Data presented as mean+/−SEM. N = 6 wells per group. β-actin was used as an internal standard for protein loading control. Cell media were used to measure protein concentration of released IL-1β (d) and IL-18 (e). Data presented as mean+/−SEM. N = 5–6 wells per group. **p < 0.05 compared to 6.8 and *p < 0.05 compared to 7.4. Data on a, b and c were obtained from lysates measured by immunoblotting, and data from d to e correspond to supernatants measured by a Simple Plex Assay