). Intracellular production of ROS was quantified using the H2DCF-DA fluorometric method. Briefly, BMDCs were labeled with H2DCF-DA (20 μM; BioChemika Fluka) for 30 min and then

washed BI 2536 concentration with PBS before 2 × 105 cells per well were seeded into black 96-well plates. Cells were stimulated in triplicate with MSU (250 μg/mL) or H2O2 (100 mM) for 5 h before fluorescence was measured using the Infinite M200 plate reader (Tecan; excitation 485 nm, emission 538 nm). ROS levels are displayed as the percentage increase in ROS relative to untreated control samples, with error represented as the coefficient of variation (% CV). Cellular 8-oxoG was detected using the OxyDNA assay kit (Calbiochem) according to manufacturer’s instructions. Briefly, cells were harvested and fixed in 4% paraformaldehyde in PBS for 20 min at 4°C. The cells were then permeabilized in 0.1% Triton X-100 in PBS for 15 min at room temperature. C646 chemical structure After several washes, the cells were stained for 2 h at room temperature with a FITC-conjugated probe that binds 8-oxoG. The cells were then washed three times, mounted onto glass slides (Biomedia),

and viewed with a confocal microscope (Oympus IX81, Fluoview 1000, 20× magnification). Quantitative RT-PCR was performed using the following validated SYBR Green primers: peroxiredoxin1, 5′-TTGATGGTATCACTGC CAGG-3′ and 5′-CCGCTCTGTGGATGAGATTA-3′; catalase, 5′-CC CGCGGTCATGATATTAAGT-3′ and 5′-GATGAAGCAGTGGAAG GAGC-3′; Nur77, 5′-GGCTGGAGATGCCCTGTAT-3′ and 5′-GGTGT CAAACTCTCCGGTGT-3′; Xiap, 5′-CGCCTTAGCTGCTCTTCAGT-3′ and 5′-GGTCCTGATTGCAGATCTTGT-3′; Birc3, 5′-TCTGGGGATG TAGTTTTGTGC-3′ and 5′-CCGGAGATCAGAGGTCATTG-3′. Amplification was performed using an Applied Biosystems 7500 Real-Time PCR System. The relative expression level of each gene was evaluated using the ΔΔCt method. The difference between the Ct of the target gene and the Ct of the Hprt housekeeping gene was normalized to the ΔCt of the untreated condition. Mice were injected

i.p. with 3 mg MSU crystals in 0.5 mL PBS. Control mice were injected with PBS alone. After 6 h, peritoneal exudate cells were collected by lavage with cold medium, centrifuged, and RBC lysis was performed using hypotonic ammonium chloride solution for 1 min. Total cellular extract was prepared from the remaining Suplatast tosilate cells. BMDCs were treated with MSU (250 μg/mL). Cell survival was assessed by PI staining and LDH. For PI staining, cells were washed and resuspended in 70% prechilled ethanol, then fixed in the dark for 30 min on ice. After treatment with RNAse A (100 mg/mL, Roche) for 30 min at 37°C, nucleic acids were stained with PI (50 mg/mL; Invitrogen) and data were acquired by FACSCalibur flow cytometer (BD Biosciences) and analyzed using FlowJo software (Tree Star). LDH released into the supernatant was monitored using CytoTox 96 Non-Radioactive Cytotoxicity Assay (Promega) following manufacturer’s protocol (Promega).