Fig. 1
From: SiO2 and TiO2 nanoparticles synergistically trigger macrophage inflammatory responses
Synergistic inflammation by SiO2 and TiO2 nanoparticles (NPs). a LPS-primed C57BL/6 mouse bone marrow-derived macrophages (BMDMs) were untreated (white columns) or pretreated with YVAD-CHO (20 μM: black columns) and were stimulated with SiO2 NPs and/or TiO2 NPs (10 μg/cm3 each) for 4 h at 37 °C. The amount of IL-1β in culture supernatants was measured by ELISA. Data are shown as mean + S.D. N.D.; not detected. b LPS-primed BMDMs were unstimulated or stimulated with SiO2 NPs and/or TiO2 NPs (10 μg/cm3) for 2 h at 37 °C. Maturation of caspase-1 and IL-1β in pooled supernatants and cell extracts were analyzed by immunoblot. c, d C57BL/6 mice were intratracheally treated with PBS alone or with SiO2 NPs and/or TiO2 NPs (5 mg/kg each) (N = 4 per group). Twenty-four h after injection, lung inflammation was analyzed by micro-computed tomography in c. Bronchoalveolar lavage fluid (BALF) was harvested from these mice, and total cell number in BALF was counted. Then cells were stained with fluorescently-labeled anti-Gr-1 mAb and analyzed by flow cytometry. Gr-1-positive cell number in BALF was calculated and indicated as the mean + S.D. in d. Analysis of variance (ANOVA) F (3,12) = 12.8, P < 0.01 for treatment groups. *P < 0.05 to the others, Holm’s post hoc test. Similar results were obtained in three independent studies