Caveolin1 and YAP drive mechanically induced mesothelial to mesenchymal transition and fibrosis

Cell Death Dis. 2020 Aug 3;11(8):647. doi: 10.1038/s41419-020-02822-1.


Despite their emerging relevance to fully understand disease pathogenesis, we have as yet a poor understanding as to how biomechanical signals are integrated with specific biochemical pathways to determine cell behaviour. Mesothelial-to-mesenchymal transition (MMT) markers colocalized with TGF-β1-dependent signaling and yes-associated protein (YAP) activation across biopsies from different pathologies exhibiting peritoneal fibrosis, supporting mechanotransduction as a central driving component of these class of fibrotic lesions and its crosstalk with specific signaling pathways. Transcriptome and proteome profiling of the response of mesothelial cells (MCs) to linear cyclic stretch revealed molecular changes compatible with bona fide MMT, which (i) overlapped with established YAP target gene subsets, and were largely dependent on endogenous TGF-β1 signaling. Importantly, TGF-β1 blockade blunts the transcriptional upregulation of these gene signatures, but not the mechanical activation and nuclear translocation of YAP per se. We studied the role therein of caveolin-1 (CAV1), a plasma membrane mechanotransducer. Exposure of CAV1-deficient MCs to cyclic stretch led to a robust upregulation of MMT-related gene programs, which was blunted upon TGF-β1 inhibition. Conversely, CAV1 depletion enhanced both TGF-β1 and TGFBRI expression, whereas its re-expression blunted mechanical stretching-induced MMT. CAV1 genetic deficiency exacerbated MMT and adhesion formation in an experimental murine model of peritoneal ischaemic buttons. Taken together, these results support that CAV1-YAP/TAZ fine-tune the fibrotic response through the modulation of MMT, onto which TGF-β1-dependent signaling coordinately converges. Our findings reveal a cooperation between biomechanical and biochemical signals in the triggering of MMT, representing a novel potential opportunity to intervene mechanically induced disorders coursing with peritoneal fibrosis, such as post-surgical adhesions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / metabolism*
  • Adaptor Proteins, Signal Transducing / physiology
  • Animals
  • Caveolin 1 / metabolism*
  • Caveolin 1 / physiology
  • Caveolins / metabolism
  • Disease Models, Animal
  • Epithelial Cells / metabolism
  • Epithelial-Mesenchymal Transition / genetics
  • Female
  • Humans
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Peritoneal Dialysis / methods
  • Peritoneal Fibrosis / genetics
  • Peritoneal Fibrosis / metabolism*
  • Peritoneal Fibrosis / pathology
  • Peritoneum / metabolism
  • Signal Transduction / drug effects
  • Smad3 Protein / metabolism
  • Tissue Adhesions / metabolism
  • Transcription Factors / metabolism*
  • Transcription Factors / physiology
  • Transforming Growth Factor beta1 / metabolism
  • YAP-Signaling Proteins


  • Adaptor Proteins, Signal Transducing
  • CAV1 protein, human
  • Caveolin 1
  • Caveolins
  • Smad3 Protein
  • Transcription Factors
  • Transforming Growth Factor beta1
  • YAP-Signaling Proteins
  • YAP1 protein, human