Caspase 1 assay kit

The caspase-1 activity was determined by a caspase-1 assay kit (Beyotime Institute of Biotechnology, Shanghai, China). A piece of liver (10 ± 0.1 mg) was homogenized with 100 μL ice-cold lysis buffer and then was incubated for 5 min. After centrifuged at 20000 g, 4°C for 10 min, the supernatants were retrieved and aliquots corresponding to protein at the concentration of 1-3 mg/mL. 40 μL caspase-1 buffer and 10 μL YVAD-pNA (2 mM) substrate were added to each sample. The samples were then incubated at 37°C for 2 h. The absorbance was recorded at 405 nm using Tecan Infinite 200 Pro (Tecan Group Ltd., Mannedorf, Switzerland). The activity of caspase substrates was expressed as a percentage of enzyme activity compared with the controls.

Caspase-1 activity was assessed using a caspase-1 assay kit (Beyotime Biotechnology). The absorbance was detected using a microplate reader at 405 nm.