Fig. 4

Butyrate suppressed NLRP3 inflammasome activation in vivo and in vitro. A Representative view of calvarium in each group via Micro-CT 3D reconstruction. B–D Quantification of bone erosion parameters (BV/TV) bone volume to tissue volume ratio, (BMD) bone mineral density, and total porosity. n = 6. E Percentage of osteoclasts surface per bone surface (OCs/BS, %). n = 5. F, G BMDMs were incubated with Ti particles (0.1 mg/ml) and butyrate (1 mM) for 6 h after being primed with LPS (100 ng/ml) for 3 h, then cell lysates and supernatants were used for analysis of western blot. Cleaved Caspase-1 (P20) was detected from supernatant samples. NLRP3, Caspase-1 pro, IL-1β pro and Actin were detected in cell lysates (F). IL-1β were detected from supernatant samples (G). n = 3. H Representative immunohistochemical staining of NLRP3 and IL-1β. I Quantification of NLRP3 and IL-1β expression using integrated optical density/specimen area (IOD/Area). J Representative immunofluorescence staining of Caspase-1 in calvarial specimens. K Quantification of Caspase-1 using mean density (integrated density/specimen area) in calvarial specimens. n = 5. Results are expressed as mean ± SEM (One-way ANOVA[post hoc:SNK] **p < 0.01, ***p < 0.001)