Transforming growth factor (TGF)-β1-induced miR-133a inhibits myofibroblast differentiation and pulmonary fibrosis

Cell Death Dis. 2019 Sep 11;10(9):670. doi: 10.1038/s41419-019-1873-x.


Transforming growth factor (TGF)-β1, a main profibrogenic cytokine in the progression of idiopathic pulmonary fibrosis (IPF), induces differentiation of pulmonary fibroblasts to myofibroblasts that produce high levels of collagen, leading to concomitantly loss of lung elasticity and function. Recent studies implicate the importance of microRNAs (miRNAs) in IPF but their regulation and individual pathological roles remain largely unknown. We used both RNA sequencing and quantitative RT-PCR strategies to systematically study TGF-β1-induced alternations of miRNAs in human lung fibroblasts (HFL). Our data show that miR-133a was significantly upregulated by TGF-β1 in a time- and concentration-dependent manner. Surprisingly, miR-133a inhibits TGF-β1-induced myofibroblast differentiation whereas miR-133a inhibitor enhances TGF-β1-induced myofibroblast differentiation. Interestingly, quantitative proteomics analysis indicates that miR-133a attenuates myofibroblast differentiation via targeting multiple components of TGF-β1 profibrogenic pathways. Western blot analysis confirmed that miR-133a down-regulates TGF-β1-induced expression of classic myofibroblast differentiation markers such as ɑ-smooth muscle actin (ɑ-SMA), connective tissue growth factor (CTGF) and collagens. miRNA Target Searcher analysis and luciferase reporter assays indicate that TGF-β receptor 1, CTGF and collagen type 1-alpha1 (Col1a1) are direct targets of miR-133a. More importantly, miR-133a gene transferred into lung tissues ameliorated bleomycin-induced pulmonary fibrosis in mice. Together, our study identified TGF-β1-induced miR-133a as an anti-fibrotic factor. It functions as a feed-back negative regulator of TGF-β1 profibrogenic pathways. Thus, manipulations of miR-133a expression may provide a new therapeutic strategy to halt and perhaps even partially reverse the progression of IPF.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Actins / genetics
  • Actins / metabolism
  • Animals
  • Bleomycin / toxicity
  • Cell Differentiation / drug effects
  • Cell Differentiation / genetics*
  • Collagen Type I / genetics
  • Collagen Type I / metabolism
  • Connective Tissue Growth Factor / genetics
  • Connective Tissue Growth Factor / metabolism
  • Female
  • HEK293 Cells
  • Humans
  • Idiopathic Pulmonary Fibrosis / chemically induced
  • Idiopathic Pulmonary Fibrosis / genetics
  • Idiopathic Pulmonary Fibrosis / metabolism*
  • Idiopathic Pulmonary Fibrosis / pathology
  • Mice
  • Mice, Inbred C57BL
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • Myofibroblasts / drug effects
  • Myofibroblasts / metabolism*
  • NIH 3T3 Cells
  • Proteomics
  • Smad3 Protein / genetics
  • Smad3 Protein / metabolism
  • Transforming Growth Factor beta1 / genetics
  • Transforming Growth Factor beta1 / metabolism
  • Transforming Growth Factor beta1 / pharmacology*
  • p38 Mitogen-Activated Protein Kinases / genetics
  • p38 Mitogen-Activated Protein Kinases / metabolism


  • ACTA2 protein, human
  • Actins
  • CCN2 protein, human
  • Collagen Type I
  • MIRN133 microRNA, human
  • MicroRNAs
  • Mirn133 microRNA, mouse
  • Smad3 Protein
  • TGFB1 protein, human
  • Transforming Growth Factor beta1
  • collagen type I, alpha 1 chain
  • Bleomycin
  • Connective Tissue Growth Factor
  • p38 Mitogen-Activated Protein Kinases