Fig. 1

miR-302b expression altered after MSU treatment and repressed MSU-induced IL-1β expression in vitro. a Time-dependent IL-1β production in THP-1 cells. THP-1 cells treated with 150 μg/ml MSU and cell supernatant collected at a different time points from 2 to 48 h. IL-1β protein levels in THP-1 cells detected with ELISA. b THP-1 cells treated with MSU for 1 h and 12 h. Cell lysates analyzed for miR-302b expression with real-time qPCR. c Air pouch inflammation model made with an injection of sterile air. Six hours after injection of MSU crystals, three mice were anesthetized and air pouch membranes collected. Expression of miR-302b detected using real-time qPCR. d Real-time qPCR analysis of miR-302b expression in THP-1 cells transfected with miRNA negative control (NS-m) or miR-302b mimics (302b-m). e Real-time qPCR analysis of IL-1β mRNA levels in miRNA NS-m or 302b-m-transfected THP-1 cells after treatment with MSU. f ELISA analysis of IL-1β protein levels in cell culture medium 8 h after MSU treatment. THP-1 cells transfected as indicated in (e). Data represent three experiments, shown as means ± SEMs (***p < 0.001, **p < 0.01, *p < 0.05 by t-test). IL-1β interleukin-1β, MSU monosodium urate, CTRL control