Figure 4

qRT-PCR gene expression of select pro-inflammatory genes in HAEC in response to Libby amphibole with comparison to the standard reference amosite samples dosed on an equal mass basis. Relative gene expression of the pro-inflammatory mediators TNF (TNF-a), IL-6, PTGS2 (COX-2) and IL8 measured by qRT-PCR following a 24 h exposure of HAEC to increasing doses of the four amphibole samples. HAEC were exposed on an equal mass basis to 2.64 (white bars), 13.2 (gray bars) or 26.4 (black bars) mg per cellular surface area (mg/cm²) to each of the amphibole samples. Data are presented as means ± SEM and are expressed as fold increase with respect to the vehicle-only control. Significant increases (p < 0.05) in mRNA transcript with respect to the vehicle-only control are denoted with an asterisk (*). Significant difference in response (p < 0.05) from LA2000 (#), LA2007 (≠), UICC amosite (∂).