A CSF-1 receptor inhibitor inhibits bleomycin–induced lung fibrosis in mice.

<p>The CSF-1 receptor inhibitor BLZ945 (200 mg/kg, open circles), vehicle (20% Captisol) (closed circles) or saline (None group, closed triangles) were administered into wild-type mice given bleomycin once daily by oral gavage. Control wild-type mice (closed square) received i.p. injection of saline. The lungs (A) and BALF (B-E) were collected on day 25 after starting bleomycin administration and analyzed. (A) Representative tissue images of Sirius Red–stained lung sections (Left). Magnification, x400. Scale bar, 100 μm. Quantification of fibrotic areas in Sirius Red–stained lung sections (Right). N, none; V, vehicle; B, BLZ945. (B-E) Macrophage numbers (B), soluble collagen levels (C), total protein concentrations (D), and total cell numbers (E) in BALF. The individual values and the mean ± SEM are shown. N = 4−7 from the single experiments, except the saline-administered wild-type control mice in which N was 20 from multiple experiments in (A) and 2 in (B-E). *P <0.05 (one-way ANOVA followed by the Bonferroni post-test).