(A) RT-qPCR of Igf-1 gene expression in AKR-2B murine fibroblasts treated with TGFβ compared to vehicle over 24 hours (n=3). (B) RT-qPCR of Igf-1 gene expression in whole lung tissue from intratracheal Bleomycin (BLM, n=5) treated mice compared to Saline (n=5). (C) Western blot and (D) ELISA analysis of IGF-1 ligand expression/secretion following TGFβ or vehicle treatment in AKR-2B fibroblasts over 24 hours (n=3 for both). (E) IGF-1 receptor (IGF-1R) was immunoprecipitated (IP) from AKR-2B murine fibroblasts at the indicated times following treatment with TGFβ (+) or vehicle (−) and Western blotted (WB) for p-IGF-1R (n=3). Data are presented as means −/+ Standard Error of the Mean (SEM) for the number of biological replicates indicated (n). Statistical significance was determined after computing single factor ANOVA and/or unpaired two-tailed Student’s t-test (p<0.05 (*), p<0.01 (**), p<0.005 (***), p<0.001 (****). Results demonstrate that TGFβ stimulates Igf-1 gene expression, ligand production, and IGF-1R activation in murine fibroblasts.