title: Association of histone acetylation at the ACTA2 promoter region with epithelial mesenchymal transition of lens epithelial cells.
abstract: OBJECTIVE
  Epithelial mesenchymal transition (EMT) plays a central role in the development of fibrotic complications of the lens. The current study is designed to check whether EMT of lens epithelial cells (LECs) is regulated by epigenetic modifications and to evaluate the effect of Trichostatin-A (TSA) on the transforming growth factor-β (TGF-β)-induced EMT.
  
  
  METHODS
  Fetal human LECs (FHL124) were treated with TGF-β2 in the presence or absence of TSA. Levels of mRNA, protein, as well as localization of α-smooth muscle actin (αSMA) were studied along with migration of LECs. Acetylation of histone H4 was analyzed and chromatin immunoprecipitation (ChIP) was carried out to study the level of acetylated histone H4 at the promoter of αSMA gene (ACTA2). Student's t-test was used for statistical analysis.
  
  
  RESULTS
  TGF-β2 treatment resulted in myofibroblast-like changes and increased migratory capacity of FHL124. Protein and mRNA expression of αSMA increased, and immunofluorescence revealed presence of extensive stress fibers. TSA treatment preserved epithelial morphology, retarded cell migration, and abrogated an increase in αSMA levels. TSA led to the accumulation of acetylated histone H4 that was reduced on TGF-β2 treatment. However, increased level of histone H4 acetylation was found at the ACTA2 promoter region during TGF-β treatment.
  
  
  CONCLUSIONS
  The increased level of αSMA, a hallmark of EMT in LECs, is associated with increased level of histone H4 acetylation at its promoter region, and TSA helps in suppressing EMT by epigenetically reducing this level. TSA thus shows promising potential in management of fibrotic conditions of the lens.
authors: Cell and Molecular Biology, Iladevi Cataract and IOL Research Centre, Ahmedabad, India.
authors: D A
authors: DA
authors: Ganatra
authors: Cell and Molecular Biology, Iladevi Cataract and IOL Research Centre, Ahmedabad, India.
authors: S
authors: S
authors: Rajkumar
authors: Cell and Molecular Biology, Iladevi Cataract and IOL Research Centre, Ahmedabad, India.
authors: A R
authors: AR
authors: Patel
authors: Cell and Molecular Biology, Iladevi Cataract and IOL Research Centre, Ahmedabad, India.
authors: D U
authors: DU
authors: Gajjar
authors: Cell and Molecular Biology, Iladevi Cataract and IOL Research Centre, Ahmedabad, India.
authors: K
authors: K
authors: Johar
authors: Cell and Molecular Biology, Iladevi Cataract and IOL Research Centre, Ahmedabad, India.
authors: A I
authors: AI
authors: Arora
authors: Cell and Molecular Biology, Iladevi Cataract and IOL Research Centre, Ahmedabad, India.
authors: F B
authors: FB
authors: Kayastha
authors: Cell and Molecular Biology, Iladevi Cataract and IOL Research Centre, Ahmedabad, India.
authors: A R
authors: AR
authors: Vasavada
mesh_terms: D000107:Acetylation; D000199:Actins / Q000378:metabolism*; D015153:Blotting, Western; D002465:Cell Movement / Q000187:drug effects; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D058750:Epithelial-Mesenchymal Transition; D005333:Fetus; D019084:Fluorescent Antibody Technique, Indirect; D056572:Histone Deacetylase Inhibitors / Q000494:pharmacology; D006657:Histones / Q000378:metabolism*; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology; D007908:Lens, Crystalline / Q000166:cytology; D011401:Promoter Regions, Genetic / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D053781:Transforming Growth Factor beta2 / Q000037:antagonists & inhibitors / Q000494:pharmacology
chemical_list: C541116:ACTA2 protein, human; D000199:Actins; D056572:Histone Deacetylase Inhibitors; D006657:Histones; D006877:Hydroxamic Acids; D012333:RNA, Messenger; D053781:Transforming Growth Factor beta2; C012589:trichostatin A