Figure 4
BEAS 2B steady state mRNA levels over time with exposure to silica particles of stress-related and immune response genes. Time-course analysis of mRNA levels by QRT-PCR of BEAS 2B cells exposed to 75 × 106μm2/cm2 cristobalite (black bars) and amorphous silica (gray bars) and unexposed controls (white bars) for 2, 4, 8 and 24 h. Fold change in mRNA of (A) FOS, (B) ATF3, (C) IL6 and (D) IL8. *P < 0.05 compared to unexposed controls. Bars denote mean ± SEM. Results from two independent experiments were pooled (N = 6/group/time-point). Values of cells exposed to amorphous silica at 2 and 4 hours (N = 5/group/time-point).