Lovastatin inhibits TGF-beta-induced myofibroblast transdifferentiation in human tenon fibroblasts

Invest Ophthalmol Vis Sci. 2008 Sep;49(9):3955-60. doi: 10.1167/iovs.07-1610. Epub 2008 Apr 17.

Abstract

Purpose: The transdifferentiation of Tenon fibroblasts to myofibroblasts is a pivotal step in filtering bleb scarring. It is mediated by the cytokine TGF-beta, Rho-dependent contractility, and cell-matrix interactions in an interdependent fashion. HMG-CoA-reductase inhibitors (statins) have been shown to inhibit Rho-GTPase signaling; therefore, the authors studied the influence of lovastatin on TGF-beta-mediated myofibroblast transdifferentiation to assess the potential use of statins in wound healing modulation.

Methods: Human Tenon fibroblasts were grown in culture, pretreated with lovastatin, lovastatin and mevalonate, or specific inhibitors of farnesyl transferase or geranylgeranyl transferase and were stimulated with TGF-beta1. alpha-Smooth muscle actin (alpha-SMA) and connective tissue growth factor (CTGF) transcription were assessed by real-time PCR. alpha-SMA protein expression and localization were studied by Western blot and confocal immunofluorescence microscopy. Cell contractility was determined in collagen gel contraction assays. Phosphorylation of the signaling proteins Smad-2/3 and p38 were detected by Western blot, and Smad-2/3 localization was determined by confocal immunofluorescence microscopy.

Results: Lovastatin inhibited TGF-beta-induced CTGF transcription, alpha-SMA expression and incorporation into actin stress fibers, and subsequent collagen gel contraction. These effects were reversed by mevalonate. The inhibition of geranylgeranyl transferase but not farnesyl transferase blocked TGF-beta-induced alpha-SMA expression. Lovastatin decreased TGF-beta-induced p38 activation, whereas Smad-2/3 phosphorylation and nuclear translocation were preserved.

Conclusions: Lovastatin inhibits TGF-beta-induced myofibroblast transdifferentiation in human Tenon fibroblasts, most likely by interfering with Rho-signaling. Statins may, therefore, serve to inhibit scarring after filtering glaucoma surgery.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / drug effects
  • Actins / metabolism
  • Cell Differentiation / drug effects
  • Cell Differentiation / physiology*
  • Cell Transdifferentiation
  • Connective Tissue Growth Factor
  • Fibroblasts / drug effects
  • Fibroblasts / physiology*
  • Humans
  • Hydroxymethylglutaryl-CoA Reductase Inhibitors / pharmacology
  • Immediate-Early Proteins / drug effects
  • Immediate-Early Proteins / genetics
  • Intercellular Signaling Peptides and Proteins / genetics
  • Lovastatin / pharmacology*
  • Myofibrils / drug effects
  • Myofibrils / physiology*
  • RNA / genetics
  • RNA / isolation & purification
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transcription, Genetic / drug effects
  • Transforming Growth Factor beta / antagonists & inhibitors*
  • Transforming Growth Factor beta / physiology*
  • Wound Healing / drug effects
  • Wound Healing / physiology*

Substances

  • Actins
  • CCN2 protein, human
  • Hydroxymethylglutaryl-CoA Reductase Inhibitors
  • Immediate-Early Proteins
  • Intercellular Signaling Peptides and Proteins
  • Transforming Growth Factor beta
  • Connective Tissue Growth Factor
  • RNA
  • Lovastatin