MTT assay:
RAW Blue cell line viability was assessed by the mitochondrial metabolization of the tetrazolium salt 3-(4,5-methyltiazol- 2yl-)-2,5diphenyl-tetrazolium bromide] (MTT) (Applichen, Germany) colorimetric assay. Cells were maintained and plated as explained previously. The same treatment used for QuantiBlue assay was performed. Then MTT (0.5 mg·ml−1) was added, and cells were incubated at 37°C for 2 hours. Cell media was removed and formazan crystals were dissolved in DMSO. Optical density was measured at 570 nm (OD570) on a microplate spectrophotometer (PherastarFSX, BMG Lab, UK).
ELISA:
Measurement of the protein levels of CXCL1 and CCL2 from peritoneal lavage fluids, or secreted into cell supernatants from 1.5 × 106 resident peritoneal macrophages was performed by ELISA (R&D Systems) according to the manufacturer’s instructions.