Skip to main content
. 2018 Aug 23;3(16):e99543. doi: 10.1172/jci.insight.99543

Figure 2. CHOP mediates the effects of ER stress on epithelial cell apoptosis and lung fibrosis.

Figure 2

(A–E) WT and CHOP–/– mice were studied using the repetitive bleomycin model (Rep Bleo), and lungs were harvested 2 weeks after the last dose. (A) Representative Masson’s trichrome–stained lung sections. Scale bars: 800 μm. (B) Evaluation of fibrosis by morphometry. (C) Quantification of total soluble collagen in right lower lobe (RLL) by Sircol assay. (D) Fibronectin measurement by ELISA. (E) Quantification of dual immunofluorescence for pro-SPC+ and TUNEL+ cells per high-power field (HPF) on lung sections. Comparisons between groups were made using unpaired, 2-tailed Student’s t test (B and D) or 1-way ANOVA with Tukey’s post hoc test (C and E). *P < 0.05 compared with WT + rep bleo, **P < 0.05 compared with untreated WT. (F–H) Inducible transgenic mice expressing L188Q mutant surfactant protein C (L188Q SFTPC), CHOP–/– mice, L188Q SFTPC/CHOP–/– mice, and WT mice were treated with doxycycline (2 g/l) for 1 week followed by intratracheal injection of bleomycin (0.08 units), and lungs were harvested 3 weeks after bleomycin. (F) Morphometric evaluation of fibrosis. (G) Total soluble collagen in RLL by Sircol assay. (H) Densitometry on Western blot for CHOP from lung tissue lysates. β-Actin was used for normalization. *P < 0.05 compared with other groups by 1-way ANOVA with Tukey’s post hoc test (F–H).