Figure 3. Nintedanib intervention is not additive to Ptgfr deficiency in I^ER-Sftpc^I73T mice.

(A) Daily nintedanib intervention (60 mg/kg) was initiated at D12 after TAM induction. Following 16 days of intervention, surviving mice were euthanized and processed to evaluate fibrotic endpoints. (B) Weight loss as a percent of starting weight was tracked throughout the study; nintedanib intervention in I^ER-Sftpc^I73T/Ptgfr^–/– mice did not reduce mean weight loss. (C) Kaplan-Meier survival analysis by log-rank testing demonstrates a nonsignificant improved probability of survival in I^ER-Sftpc^I73T/Ptgfr^–/– that was not improved through nintedanib intervention. (D) Representative histology from I^ER-Sftpc^I73T/Ptgfr^+/+, I^ER-Sftpc^I73T/Ptgfr^–/–, and nintedanib-treated I^ER-Sftpc^I73T/Ptgfr^–/– mice 28 days after TAM and development of fibrosis. Images are derived from H&E-stained sections. Scale bars: 300 μM. (E) Soluble collagen in BALF as measured by Sircol assay and fibrillar collagen in histological sections measured by PSR staining demonstrated a significant decrease in I^ER-Sftpc^I73T/Ptgfr^–/– mice; again, nintedanib treatment did not improve these outcomes. Quantification of PSR was performed using ImageJ, and data represent percentage of total section area. Survival and weight loss data are derived from I^ER-Sftpc^I73T/Ptgfr^+/+ (n = 26), I^ER-Sftpc^I73T/Ptgfr^–/– without nintedanib (n = 12), and I^ER-Sftpc^I73T/Ptgfr^–/– with nintedanib (n = 12). Soluble collagen and PSR analysis included I^ER-Sftpc^I73T/Ptgfr^+/+ (n = 14), I^ER-Sftpc^I73T/Ptgfr^–/– without nintedanib (n = 11), and I^ER-Sftpc^I73T/Ptgfr^–/– with nintedanib (n = 7). Ordinary 1-way ANOVA testing was performed. *P < 0.05.