Bleomycin-induced Pulmonary Fibrosis

The protocol for the use of animals was approved by the Institutional Animal Care and Use Committee at the University of Chicago. Male C57BL/6J mice (8–12 wk old; Jackson Laboratory) were intubated to intratracheally administer bleomycin (1.0 IU/kg; Fresenius Kabi). Mice were killed after 14 or 21 days as indicated, as we have previously reported (14–17). For NCT-503 experiments, mice were treated with NCT-503 (40 mg/kg intraperitoneally, daily) or vehicle (5% ethanol, 35% polyethylene glycol 300 [Sigma], and 60% aqueous 30% solution of hydroxypropyl-β-cyclodextrin [Sigma]), starting on Day 8 after bleomycin instillation. For serine/glycine dietary restriction experiments, mice were switched to control or serine/glycine-free diet (TestDiet 5CC7 or 5W53, respectively; TestDiet) on the day of bleomycin instillation.

For enhanced green fluorescent protein labeling of lung fibroblasts, 3-week-old ROSA^mT/mG; Col1a2-CreERT2^+/− mice were injected with tamoxifen (1 mg in corn oil) daily for 5 days, as described previously (18). At 8 weeks, mice were treated with bleomycin. For details on cell sorting and imaging, see the data supplement.