Fig. 6.

Transcriptomic profiling does not reveal evidence of activation of the ISR in alveolar macrophage populations during lung fibrosis. (A) Transcriptomes of sorted monocyte-derived alveolar macrophages in young adult and old mice exposed to bleomycin (day 21) with and without ISRIB treatment. k-means clustering of all differentially expressed genes (ANOVA-like test on negative binomial generalized log-linear model, FDR q-value < 0.05). (Right) The characteristic Gene Ontology biological processes and genes associated with each cluster. (B) Representative flow cytometry plots gated on CD45⁺CD64⁺ macrophages in old Cx₃cr1^ERCre × zsGreen mice treated with tamoxifen 1 d prior to administration of bleomycin (see Fig. 5A for design). Median fluorescence intensity (MFI) of Siglec F levels on GFP-positive alveolar macrophages (AM) in young and old mice 21 d after bleomycin, with and without ISRIB treatment. Data are shown as mean ± SEM, 3 to 5 mice per group. Unpaired t test. *P < 0.05.