Figure 3

Mechanism of MWCNT induced pro-inflammatory response in HBE cells. A-C) A dose response of cytokine secretion (IL-1β, IL-18, IL-8) in cell culture supernatants of HBE cells exposed to MWCNT (1.5-24 μg/mL) for 24 hours. LPS (1 μg/mL) was used as positive control. Quantity of cytokines in cell culture supernatants was estimated using commercially available ELISA/Bioplex kits. D) Modulation of IL-1β production after pretreatment with pharmacological inhibitors of caspase-1 (Z-WEHD-FMK) and cathepsin B (CA-074Me) or pore blocking agent (glycine). Cells were pre-treated with these inhibitors as described in Materials and methods and levels of IL-1β in cell culture supernatants were quantified by commercially available ELISA. E- G) Modulation of IL-1β, IL-18 and IL-8 production by specific siRNA against NLRP3 inflammasome. Data were analyzed by analysis of variance (ANOVA) followed by Tukey’s post hoc test. Graphs show average ± SEM of three independent experiments with triplicate of each condition, *p < 0.05, **p < 0.01 and ***p < 0.001, ****p < 0.0001 (between media-treated control and treatment).