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Development of an In Vitro Assay to Evaluate Contractile Function of Mesenchymal Cells that Underwent Epithelial-Mesenchymal Transition
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TGFbeta1-dependent contraction of fibroblasts is mediated by the PDGFalpha receptor

Yasushi Ikuno1, Andrius Kazlauskas

  • 1Department of Ophthalmology, The Schepens Eye Research Institute, Harvard Medical School, Boston, Massachusetts 02114, USA.

Investigative Ophthalmology & Visual Science
|January 5, 2002
PubMed
Abstract

Insights

Transforming growth factor-beta (TGFbeta) is the main driver of vitreous-induced fibroblast contraction in eye fibrotic diseases like PVR. This contraction partly involves the PDGFalpha receptor (alphaPDGFR), indicating its role in mediating growth factor effects.

Area of Science:

  • Ophthalmology
  • Cell Biology
  • Fibrosis Research

Background:

  • Fibrotic diseases of the eye, such as proliferative vitreoretinopathy (PVR), involve fibroblast contraction and tractional forces.
  • Transforming growth factor-beta (TGF-beta) and platelet-derived growth factor (PDGF) are key growth factors implicated in PVR development.

Purpose of the Study:

  • To investigate the relationship between TGF-beta1 and PDGF in the context of fibroblast cellular contraction.
  • To elucidate the role of PDGF receptors (PDGFRs) in mediating TGF-beta1-induced cellular contraction.

Main Methods:

  • Utilized an in vitro type I collagen gel contraction assay with fibroblast cell lines expressing PDGFalpha receptor (alphaPDGFR), PDGFbeta receptor (betaPDGFR), or no PDGFR.
  • Tested the effects of rabbit vitreous, TGFbeta1, and PDGF on cellular contraction.

Main Results:

  • Rabbit vitreous induced significant cellular contraction, with 60% of this activity neutralized by TGFbeta antibodies.
  • Fibroblast cells expressing alphaPDGFR showed a greater response to vitreous and TGFbeta1 compared to those expressing betaPDGFR or no PDGFR.
  • TGFbeta1 promoted tyrosine phosphorylation of both PDGFRs, with a stronger effect on alphaPDGFR, suggesting an indirect role in TGFbeta-dependent contraction.

Conclusions:

  • TGFbeta is identified as the primary factor in vitreous-induced fibroblast contraction.
  • The alphaPDGFR mediates a portion of TGFbeta-dependent cellular contraction, indicating an indirect signaling pathway.
  • The alphaPDGFR plays a crucial role in mediating cellular contraction in response to both TGFbeta and PDGF family members.

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