title: All-trans-retinoic acid inhibition of transforming growth factor-β-induced collagen gel contraction mediated by human Tenon fibroblasts: role of matrix metalloproteinases.
abstract: OBJECTIVE
  Scarring and contraction of the conjunctiva are common complications of many ocular diseases. We investigated the effects of all-trans-retinoic acid (ATRA) on the contractility of human Tenon's capsule fibroblasts (HTFs) cultured in a three-dimensional collagen gel.
  
  
  METHODS
  HTFs were cultured in a three-dimensional gel of type I collagen and in the absence or presence of transforming growth factor (TGF)-β, ATRA, or an inhibitor of matrix metalloproteinases (MMPs). Collagen gel contraction was evaluated by measurement of gel diameter. The release of MMPs and tissue inhibitors of metalloproteinases (TIMPs) into culture supernatants was assessed by immunoblot analysis and gelatin zymography. The release of lactate dehydrogenase activity from HTFs was measured with a colorimetric assay kit.
  
  
  RESULTS
  ATRA inhibited TGF-β-induced collagen gel contraction mediated by HTFs in a concentration- and time-dependent manner. TGF-β induced the release of MMP-1, MMP-2 and MMP-3 by HTFs, and ATRA inhibited these effects of TGF-β on MMP-1 and MMP-3 release. ATRA also stimulated TIMP-1 release from HTFs in the presence of TGF-β. Furthermore, TGF-β-induced collagen gel contraction was blocked by the MMP inhibitor GM6001. ATRA did not exhibit cytotoxicity for HTFs.
  
  
  CONCLUSIONS
  ATRA inhibited TGF-β-induced collagen gel contraction mediated by HTFs, likely in part by attenuating the production of MMP-1 and MMP-3 and by stimulating the production of TIMP-1. ATRA may therefore prove to be of clinical value for inhibition of scar formation in the conjunctiva.
authors.affiliation: Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, Ube City, Yamaguchi, Japan Department of Ophthalmology, First Hospital of Jilin University, Jilin, PR China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, Ube City, Yamaguchi, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kimura
authors.affiliation: Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, Ube City, Yamaguchi, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Orita
authors.affiliation: Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, Ube City, Yamaguchi, Japan.
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Teranishi
authors.affiliation: Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, Ube City, Yamaguchi, Japan.
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Suzuki
authors.affiliation: Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, Ube City, Yamaguchi, Japan.
authors.forename: Koh-Hei
authors.initials: KH
authors.lastname: Sonoda
mesh_terms: D000293:Adolescent; D000328:Adult; D002478:Cells, Cultured; D003094:Collagen / Q000378:metabolism*; D004151:Dipeptides / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005260:Female; D005347:Fibroblasts / Q000187:drug effects* / Q000201:enzymology; D006801:Humans; D015151:Immunoblotting; D007641:Keratolytic Agents / Q000494:pharmacology*; D008297:Male; D061965:Matrix Metalloproteinase Inhibitors / Q000494:pharmacology; D020782:Matrix Metalloproteinases / Q000502:physiology*; D058475:Tenon Capsule / Q000166:cytology*; D013997:Time Factors; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D014212:Tretinoin / Q000494:pharmacology*
chemical_list: D004151:Dipeptides; D007641:Keratolytic Agents; D061965:Matrix Metalloproteinase Inhibitors; C078131:N-(2(R)-2-(hydroxamidocarbonylmethyl)-4-methylpentanoyl)-L-tryptophan methylamide; C560822:TIMP1 protein, human; D019715:Tissue Inhibitor of Metalloproteinase-1; D016212:Transforming Growth Factor beta; D014212:Tretinoin; D003094:Collagen; D020782:Matrix Metalloproteinases