title: Extracellular matrix elasticity modulates TGF-β-induced p38 activation and myofibroblast transdifferentiation in human tenon fibroblasts.
abstract: OBJECTIVE
  Extracellular matrix and the cytokine TGF-β influence scar formation in an interdependent fashion. In this study, the impact of extracellular matrix elasticity on TGF-β-induced signal transduction and myofibroblast transdifferentiation was examined.
  
  
  METHODS
  Primary human tenon fibroblasts were seeded on collagen-coated glass coverslips (rigid environment) or collagen or polyacrylamide gels (elastic environment) of different compliance and stimulated with TGF-β. Myofibroblast transdifferentiation was assessed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blot analysis for the marker gene α-smooth muscle actin (SMA), and SMA incorporation into stress fibers was determined by confocal immunofluorescence microscopy. CTGF transcription was assessed by RT-qPCR. Signaling pathways were examined by Western blot using phosphospecific antibodies and by immunofluorescence microscopy.
  
  
  RESULTS
  TGF-β-dependent myofibroblast transdifferentiation was enhanced in a stiff environment. Increasing matrix elasticity attenuated TGF-β-induced myofibroblast transdifferentiation and the associated CTGF expression. TGF-β-induced p38 activation was reduced on elastic substrates.
  
  
  CONCLUSIONS
  The results suggest that matrix elasticity influences TGF-β-dependent activation of p38 signaling and subsequent myofibroblast transdifferentiation. Biomechanical cues represent an important determinant of scarring processes. Therefore, cellular signals elicited by mechanotransduction deserve consideration in the design of novel antifibrotic strategies.
authors: Department of Ophthalmology, University of Würzburg, Josef-Schneider-Strasse 11, Würzburg, Germany. meyer_T3@augenklinik.uni-wuerzburg.de
authors: Tobias
authors: T
authors: Meyer-ter-Vehn
authors: Hong
authors: H
authors: Han
authors: Franz
authors: F
authors: Grehn
authors: Günther
authors: G
authors: Schlunck
mesh_terms: D000199:Actins / Q000235:genetics; D015153:Blotting, Western; D018929:Cell Culture Techniques; D054338:Cell Transdifferentiation / Q000187:drug effects*; D003094:Collagen / Q000378:metabolism; D055513:Connective Tissue Growth Factor / Q000235:genetics; D004548:Elasticity / Q000502:physiology; D005109:Extracellular Matrix / Q000502:physiology*; D005347:Fibroblasts / Q000166:cytology; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D018613:Microscopy, Confocal; D058628:Myofibroblasts / Q000166:cytology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D058475:Tenon Capsule / Q000166:cytology*; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism*
chemical_list: C541116:ACTA2 protein, human; D000199:Actins; C526317:CCN2 protein, human; D016212:Transforming Growth Factor beta; D055513:Connective Tissue Growth Factor; D003094:Collagen; D048051:p38 Mitogen-Activated Protein Kinases