TGF-β activation impairs fibroblast ability to support adult lung epithelial progenitor cell organoid formation

Am J Physiol Lung Cell Mol Physiol. 2019 Jul 1;317(1):L14-L28. doi: 10.1152/ajplung.00400.2018. Epub 2019 Apr 10.

Abstract

Transforming growth factor-β (TGF-β)-induced fibroblast-to-myofibroblast differentiation contributes to remodeling in chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis, but whether this impacts the ability of fibroblasts to support lung epithelial repair remains little explored. We pretreated human lung fibroblasts [primary (phFB) or MRC5 cells] with recombinant human TGF-β to induce myofibroblast differentiation, then cocultured them with adult mouse lung epithelial cell adhesion molecule-positive cells (EpCAM+) to investigate their capacity to support epithelial organoid formation in vitro. While control phFB and MRC5 lung fibroblasts supported organoid formation of mouse EpCAM+ cells, TGF-β pretreatment of both phFB and MRC5 impaired organoid-supporting ability. We performed RNA sequencing of TGF-β-treated phFB, which revealed altered expression of key Wnt signaling pathway components and Wnt/β-catenin target genes, and modulated expression of secreted factors involved in mesenchymal-epithelial signaling. TGF-β profoundly skewed the transcriptional program induced by the Wnt/β-catenin activator CHIR99021. Supplementing organoid culture media recombinant hepatocyte growth factor or fibroblast growth factor 7 promoted organoid formation when using TGF-β pretreated fibroblasts. In conclusion, TGF-β-induced myofibroblast differentiation results in Wnt/β-catenin pathway skewing and impairs fibroblast ability to support epithelial repair likely through multiple mechanisms, including modulation of secreted growth factors.

Keywords: TGF-β, Wnt/β-catenin signaling; lung regeneration/repair; lung stem cells; mesenchymal-epithelial signaling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult Stem Cells / drug effects
  • Adult Stem Cells / metabolism*
  • Adult Stem Cells / pathology
  • Aged
  • Animals
  • Cell Communication / drug effects
  • Cell Differentiation / drug effects
  • Coculture Techniques
  • Epithelial Cell Adhesion Molecule / genetics
  • Epithelial Cell Adhesion Molecule / metabolism
  • Epithelial Cells / drug effects
  • Epithelial Cells / metabolism*
  • Epithelial Cells / pathology
  • Female
  • Fibroblast Growth Factor 7 / pharmacology
  • Fibroblasts / metabolism*
  • Fibroblasts / pathology
  • Gene Expression Profiling
  • Gene Expression Regulation
  • Hepatocyte Growth Factor / pharmacology
  • Humans
  • Lung / metabolism
  • Lung / pathology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Middle Aged
  • Myofibroblasts / drug effects
  • Myofibroblasts / metabolism
  • Myofibroblasts / pathology
  • Organoids / drug effects
  • Organoids / metabolism*
  • Organoids / pathology
  • Pulmonary Disease, Chronic Obstructive / genetics*
  • Pulmonary Disease, Chronic Obstructive / metabolism
  • Pulmonary Disease, Chronic Obstructive / pathology
  • Pyridines / pharmacology
  • Pyrimidines / pharmacology
  • Transforming Growth Factor beta / metabolism*
  • Transforming Growth Factor beta / pharmacology
  • Wnt Proteins / genetics
  • Wnt Proteins / metabolism
  • Wnt Signaling Pathway
  • beta Catenin / genetics
  • beta Catenin / metabolism

Substances

  • CTNNB1 protein, human
  • Chir 99021
  • Epithelial Cell Adhesion Molecule
  • FGF7 protein, human
  • HGF protein, human
  • Pyridines
  • Pyrimidines
  • Transforming Growth Factor beta
  • Wnt Proteins
  • beta Catenin
  • Fibroblast Growth Factor 7
  • Hepatocyte Growth Factor