MAPK phosphatase 1 inhibition of p38α within lung myofibroblasts is essential for spontaneous fibrosis resolution

Related Experiment Video

Updated: Jun 30, 2025

Oropharyngeal Administration of Bleomycin in the Murine Model of Pulmonary Fibrosis
06:03

Oropharyngeal Administration of Bleomycin in the Murine Model of Pulmonary Fibrosis

Published on: May 9, 2025

360

Sean M Fortier1, Natalie M Walker1, Loka R Penke1

  • 1Division of Pulmonary and Critical Care Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA.

The Journal of Clinical Investigation
|March 21, 2024
PubMed

Insights

MAPK phosphatase 1 (MKP1) is crucial for resolving lung fibrosis by promoting myofibroblast (MF) dedifferentiation and apoptosis. Its inhibition of p38α MAPK is essential for spontaneous fibrosis resolution after lung injury.

Area of Science:

  • Cell Biology
  • Pulmonary Medicine
  • Molecular Biology

Background:

  • Fibrosis involves pathogenic myofibroblasts (MFs) resistant to apoptosis, hindering normal tissue repair.
  • Endogenous molecular brakes are key to resolving lung fibrosis and could inform new treatments.
  • The role of MAPK phosphatase 1 (MKP1) in lung fibroblasts and fibrosis was previously unexplored.

Purpose of the Study:

  • To investigate the function of MKP1 in lung fibroblasts and its role in pulmonary fibrosis resolution.
  • To determine if MKP1 influences myofibroblast dedifferentiation and apoptosis.
  • To explore the therapeutic potential of targeting MKP1 or its downstream pathways.

Main Methods:

  • Gain- and loss-of-function studies of MKP1 in lung fibroblasts.
  • Analysis of MKP1's effect on p38α MAPK (p38α) activity.
  • Induction of lung fibrosis using bleomycin in MKP1-deficient and wild-type mice.
  • Pharmacological inhibition of p38α using VX-702 in transgenic mice.

Main Results:

  • MKP1 promotes lung MF dedifferentiation and restores apoptosis sensitivity, primarily via p38α dephosphorylation.
  • Fibroblast-specific deletion of MKP1 abrogated spontaneous resolution of bleomycin-induced lung fibrosis.
  • Treatment with the p38α inhibitor VX-702 restored fibrosis resolution in MKP1-deficient mice.

Conclusions:

  • MKP1 acts as a critical antifibrotic brake in the lung.
  • MKP1's inhibition of pathogenic p38α in lung fibroblasts is essential for resolving lung fibrosis.
  • Targeting MKP1 or p38α may offer therapeutic strategies for progressive pulmonary fibrosis.
Keywords:
Cell biologyFibrosisMolecular biologyProtein kinasesPulmonology

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