Western Blotting Analysis
Lung tissues were homogenized in RIPA in the presence of a protease inhibitor cocktail (Roche, Indianapolis, IN, USA) and Phosphatase Inhibitor Cocktail (Roche). The protein concentrations were determined by a BCA kit (Pierce, Rockford, IL, USA). Equal concentrations of protein (25 μg) were separated by SDS-PAGE on 12% acrylamide gels. The primary antibodies used were as follow: NLRP3 (Adipogen, San Diego, CA, USA), caspase 1 (p20) (Adipogen), IL-1β, pro-IL-1β (R&D Systems, Minneapolis, MN, USA), TLR2 (Millipore, Billerica, MA, USA), AANAT (Sigma), ASMT (Abcam, Boston, MA, USA) and GAPDH (KANGCHEN Biotech, Shanghai, China) for 1 h at 37°C, followed by at 4°C overnight. Blots were washed thrice with TBST and probed with appropriate secondary antibodies for 1 h at room temperature. After washing three times, the immune-reaction was analyzed using the ECL detection system (Pierce). The band density was determined by ImageJ software (NIH, Bethesda, MD, USA).