Abstract

Idiopathic pulmonary fibrosis (IPF) represents a progressive interstitial lung disease with a mean survival time of 3-5 years. Approved pharmacological therapies may slow down, but not stop disease progression. IPF pathogenesis is characterized by the deposition of excessive amounts of fibrotic extracellular matrix of activated myofibroblasts resulting in a loss of lung function. We developed a phenotypic drug discovery assay measuring fibrotic ECM deposition by primary human lung fibroblasts (pHLFs) derived from IPF patients treated with transforming growth factor beta 1 (TGFß1) and drug compounds. 1509 small molecule compounds were screened for the inhibition of TGFß1-induced ECM deposition. Deep learning-based image analysis identified 31 hit compounds. Based on the hit Tranilast with a significant inhibitory activity on TGFß1-induced fibroblast-myofibroblast-transdifferentiation and ECM deposition, structure-activity-relationship studies discovered a group of novel highly potent cinnamic acid amides, in particular N-(2-butoxyphenyl)-3-(phenyl)acrylamides and N-(2-benzoxyphenyl)-3-(phenyl)acrylamides (N23Ps). N23Ps showed high potency for the inhibition of TGFß1 dependent aSMA induction and ECM deposition. Transcriptomic and proteomic analysis showed N23Ps to inhibit specific fibrotic signatures in TGFß1-treated pHLFs as well as in a human ex vivo injury and early 3D fibrosis model using human precision cut lung slice tissue cultures (PCLS). RNA interference rescue experiments showed inhibition of TGFß1 signaling by N23Ps to be SMURF2-dependent. Local pulmonary application of N23P significantly inhibited bleomycin-induced lung function decline in a murine bleomycin-induced lung fibrosis model.