title: MMP2 activity is critical for TGFβ2-induced matrix contraction--implications for fibrosis.
abstract: OBJECTIVE
  The fibrotic lens disorder posterior capsule opacification (PCO) develops in millions of patients following cataract surgery. PCO characteristics are extensive extracellular matrix (ECM) production and contraction of the posterior lens capsule, resulting in light-scattering ECM modification (wrinkling). The pro-fibrotic cytokine transforming growth factor beta (TGFβ) is central to PCO development. This study aimed to elucidate the role of the ECM modulators matrix metalloproteinases (MMPs) in TGFβ-mediated PCO formation.
  
  
  METHODS
  The human lens epithelial cell-line FHL-124 and human capsular bag models were employed. Gene expression of MMP family members was determined by oligonucleotide microarray and quantitative real-time RT-PCR. MMP2 and MT1-MMP protein levels were analyzed by ELISA and Western blotting, respectively. Matrix contraction was determined using an FHL-124 patch contraction assay; at end-point, cells were stained with Coomassie brilliant blue and area was determined using image analysis software. Cell coverage and wrinkle formation on the posterior capsule were also assessed using human capsular bag models.
  
  
  RESULTS
  Active TGFβ2 (10 ng/mL) increased gene and protein levels of MMP2 and MT1-MMP and induced matrix contraction in FHL-124 cells. Specific siRNA inhibition of MT1-MMP did not suppress TGFβ2-induced matrix contraction. Active TGFβ2-mediated contraction was prevented by broad-spectrum MMP inhibitor GM6001 (25 μM), MMP2 siRNA, and MMP2 neutralizing antibody (4 μg/mL). TGFβ2-induced wrinkle formation was attenuated in human capsular bags treated with MMP2 neutralizing antibody (20 μg/mL).
  
  
  CONCLUSIONS
  MMP2 plays a critical role in TGFβ2-mediated matrix contraction, which appears to be independent of MT1-MMP. MMP2 inhibition provides a novel strategy for the treatment of PCO and potentially other fibrotic disorders.
authors.affiliation: School of Biological Sciences, University of East Anglia, Norwich, Norfolk, UK.
authors.forename: Julie A
authors.initials: JA
authors.lastname: Eldred
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Hodgkinson
authors.forename: Lucy J
authors.initials: LJ
authors.lastname: Dawes
authors.forename: John R
authors.initials: JR
authors.lastname: Reddan
authors.forename: Dylan R
authors.initials: DR
authors.lastname: Edwards
authors.forename: I Michael
authors.initials: IM
authors.lastname: Wormstone
mesh_terms: D015153:Blotting, Western; D002460:Cell Line; D004797:Enzyme-Linked Immunosorbent Assay; D005109:Extracellular Matrix / Q000187:drug effects* / Q000378:metabolism; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism*; D005355:Fibrosis / Q000196:embryology / Q000201:enzymology / Q000235:genetics; D005786:Gene Expression Regulation; D006801:Humans; D007150:Immunohistochemistry; D007903:Lens Capsule, Crystalline / Q000196:embryology / Q000201:enzymology*; D020778:Matrix Metalloproteinase 2 / Q000096:biosynthesis / Q000235:genetics*; D046228:Microarray Analysis; D012313:RNA / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction; D012189:Retrospective Studies; D015398:Signal Transduction; D053781:Transforming Growth Factor beta2 / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology
chemical_list: D016326:Extracellular Matrix Proteins; D053781:Transforming Growth Factor beta2; D012313:RNA; D020778:Matrix Metalloproteinase 2