Caspase-3 activity in lung and cell lysates was assayed using a Caspase-3 Colorimetric Assay Kit (Biovision, Milpitas, CA, USA) according to the manufacturer’s instructions. Myeloperoxidase (MPO) activity was measured in lung lysates and BAL cell pellets using the EnzChek Myeloperoxidase Activity Assay Kit (Life Technologies, Carlsbad, CA, USA). Total RNA was isolated from lung homogenates and cultured macrophages. Total RNA was isolated (Qiagen, Valencia, CA, USA), and specific transcripts were quantified by real-time PCR using TaqMan FAM-labeled probes (Applied Biosystems, Foster City, CA, USA) as described by Rohani et al.27 (link) Total IL-1β levels were measured using the Mouse IL-1β ELISA Ready-SET-Go! Kit (eBioscience).