title: A Novel Antifibrotic Mechanism of Nintedanib and Pirfenidone. Inhibition of Collagen Fibril Assembly.
abstract: Idiopathic pulmonary fibrosis (IPF) is characterized by excessive deposition of extracellular matrix, in particular, collagens. Two IPF therapeutics, nintedanib and pirfenidone, decelerate lung function decline, but their underlying mechanisms of action are poorly understood. In this study, we sought to analyze their effects on collagen synthesis and maturation at important regulatory levels. Primary human fibroblasts from patients with IPF and healthy donors were treated with nintedanib (0.01-1.0 μM) or pirfenidone (100-1,000 μM) in the absence or presence of transforming growth factor-β1. Effects on collagen, fibronectin, FKBP10, and HSP47 expression, and collagen I and III secretion, were analyzed by quantitative polymerase chain reaction and Western blot. The appearance of collagen fibrils was monitored by scanning electron microscopy, and the kinetics of collagen fibril assembly was assessed using a light-scattering approach. In IPF fibroblasts, nintedanib reduced the expression of collagen I and V, fibronectin, and FKBP10 and attenuated the secretion of collagen I and III. Pirfenidone also down-regulated collagen V but otherwise showed fewer and less pronounced effects. By and large, the effects were similar in donor fibroblasts. For both drugs, electron microscopy of IPF fibroblast cultures revealed fewer and thinner collagen fibrils compared with untreated controls. Finally, both drugs dose-dependently delayed fibril formation of purified collagen I. In summary, both drugs act on important regulatory levels in collagen synthesis and processing. Nintedanib was more effective in down-regulating profibrotic gene expression and collagen secretion. Importantly, both drugs inhibited collagen I fibril formation and caused a reduction in and an altered appearance of collagen fibril bundles, representing a completely novel mechanism of action for both drugs.
authors.affiliation: 1 Comprehensive Pneumology Center, and.
authors.forename: Larissa
authors.initials: L
authors.lastname: Knüppel
authors.affiliation: 2 Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, Oregon.|3 Research Department, Shriners Hospital for Children, Portland, Oregon.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Ishikawa
authors.affiliation: 4 Research Unit Analytical Pathology, Helmholtz-Zentrum München, Munich, Germany.
authors.forename: Michaela
authors.initials: M
authors.lastname: Aichler
authors.affiliation: 1 Comprehensive Pneumology Center, and.
authors.forename: Katharina
authors.initials: K
authors.lastname: Heinzelmann
authors.affiliation: 5 Thoraxchirurgisches Zentrum, Klinik für Allgemeine-, Viszeral-, Transplantations-, Gefäß- und Thoraxchirurgie, Klinikum Großhadern, and.|6 Asklepios Fachkliniken München-Gauting, Munich, Germany; and.
authors.forename: Rudolf
authors.initials: R
authors.lastname: Hatz
authors.affiliation: 7 Medizinische Klinik und Poliklinik V, Klinikum der Ludwig-Maximilians-Universität, Ludwig-Maximilians-Universität, Munich, Germany.|6 Asklepios Fachkliniken München-Gauting, Munich, Germany; and.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Behr
authors.affiliation: 4 Research Unit Analytical Pathology, Helmholtz-Zentrum München, Munich, Germany.
authors.forename: Axel
authors.initials: A
authors.lastname: Walch
authors.affiliation: 2 Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, Oregon.|3 Research Department, Shriners Hospital for Children, Portland, Oregon.
authors.forename: Hans Peter
authors.initials: HP
authors.lastname: Bächinger
authors.affiliation: 1 Comprehensive Pneumology Center, and.|8 Pulmonary and Critical Care Medicine University, Colorado Anschutz Medical Campus, Denver, Colorado.
authors.forename: Oliver
authors.initials: O
authors.lastname: Eickelberg
authors.affiliation: 1 Comprehensive Pneumology Center, and.
authors.forename: Claudia A
authors.identifier: 0000-0002-1211-7834
authors.initials: CA
authors.lastname: Staab-Weijnitz
mesh_terms: D024042:Collagen Type I / Q000378:metabolism; D015536:Down-Regulation / Q000187:drug effects; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D024022:Fibrillar Collagens / Q000378:metabolism*; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D050958:HSP47 Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000188:drug therapy* / Q000473:pathology*; D007211:Indoles / Q000494:pharmacology / Q000627:therapeutic use*; D008168:Lung / Q000473:pathology; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D011728:Pyridones / Q000494:pharmacology / Q000627:therapeutic use*; D022021:Tacrolimus Binding Proteins / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D024042:Collagen Type I; D016326:Extracellular Matrix Proteins; D024022:Fibrillar Collagens; D050958:HSP47 Heat-Shock Proteins; D007211:Indoles; D011728:Pyridones; C494660:SERPINH1 protein, human; C093844:pirfenidone; D022021:Tacrolimus Binding Proteins; C110054:FKBP10 protein, human; C530716:nintedanib
keywords: extracellular matrix; idiopathic pulmonary fibrosis; nintedanib; pirfenidone