title: Histone deacetylase inhibitors trichostatin A and vorinostat inhibit TGFβ2-induced lens epithelial-to-mesenchymal cell transition.
abstract: OBJECTIVE
  Posterior capsule opacification (PCO) after cataract surgery is due in part to proliferation of the adhering lens epithelial cells and transdifferentiation into mesenchymal cells. The histone deacetylase (HDAC) inhibitors, trichostatin A (TSA) and vorinostat (suberoylanilidehydroxamic acid [SAHA]) are known to modulate cell proliferation and epithelial-mesenchymal transition (EMT). Studies have shown that TGFβ2 can induce EMT similar to that seen during PCO. This study evaluated the effects of TSA and SAHA on TGFβ2-induced EMT in lens epithelial explants.
  
  
  METHODS
  Epithelial cells adherent to lens capsules were isolated from fresh pig lenses and human donor lenses and cultured for 12 hours. Explants were pretreated with TSA or SAHA for 1 hour and then treated with TGFβ2 for up to 3 days. Scratch wound healing assay was used to determine epithelial cell proliferation and migration in the samples. The effects of TSA and SAHA on histone acetylation and HDAC 1 to 6 levels were analyzed by Western blotting.
  
  
  RESULTS
  Western blotting and immunocytochemistry demonstrated high expression of α-SMA in lens epithelial cells treated with TGFβ2. The HDAC inhibitors exerted dose-dependent inhibition of α-SMA expression, with complete inhibition occurring with 0.5 μM of TSA and 2.5 μM of SAHA. Transforming growth factor β2-induced EMT was suppressed by TSA and SAHA. Histone deacetylase inhibition in pig lens epithelia led to increased acetylation of histone 3 and 4 at multiple sites.
  
  
  CONCLUSIONS
  Histone deacetylase inhibitors, TSA, and SAHA prevent EMT in lens epithelial explants. The results also suggest that the epigenetic modifiers are the potential targets to control PCO after cataract surgery.
authors.affiliation: Department of Ophthalmology, University of Missouri-Columbia School of Medicine, Columbia, Missouri, United States.
authors.forename: Leike
authors.initials: L
authors.lastname: Xie
authors.affiliation: Department of Ophthalmology, University of Missouri-Columbia School of Medicine, Columbia, Missouri, United States.
authors.forename: Puttur
authors.initials: P
authors.lastname: Santhoshkumar
authors.affiliation: Department of Ophthalmology, University of Missouri-Columbia School of Medicine, Columbia, Missouri, United States.
authors.forename: Lixing W
authors.initials: LW
authors.lastname: Reneker
authors.affiliation: Department of Ophthalmology, University of Missouri-Columbia School of Medicine, Columbia, Missouri, United States Department of Biochemistry, University of Missouri-Columbia School of Medicine, Columbia, Missouri, United States.
authors.forename: K Krishna
authors.initials: KK
authors.lastname: Sharma
mesh_terms: D000199:Actins / Q000096:biosynthesis* / Q000187:drug effects; D000818:Animals; D015153:Blotting, Western; D058442:Capsule Opacification / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control*; D002387:Cataract Extraction / Q000009:adverse effects; D002465:Cell Movement; D049109:Cell Proliferation; D002478:Cells, Cultured; D004195:Disease Models, Animal; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects; D005462:Fluorine Radioisotopes; D056572:Histone Deacetylase Inhibitors / Q000494:pharmacology; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology*; D007150:Immunohistochemistry; D007903:Lens Capsule, Crystalline / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D008856:Microscopy, Fluorescence; D008875:Middle Aged; D013552:Swine; D053781:Transforming Growth Factor beta2 / Q000009:adverse effects* / Q000378:metabolism; D000077337:Vorinostat
chemical_list: C541116:ACTA2 protein, human; D000199:Actins; D005462:Fluorine Radioisotopes; D056572:Histone Deacetylase Inhibitors; D006877:Hydroxamic Acids; D053781:Transforming Growth Factor beta2; C012589:trichostatin A; D000077337:Vorinostat
keywords: epigenetics; epithelial-mesenchymal transition; histone deacetylase inhibitors; lens epithelial explants; posterior capsule opacification