HDAC Inhibitor-Mediated Epigenetic Regulation of Glaucoma-Associated TGFß2 in the Trabecular Meshwork.
Invest Ophthalmol Vis Sci
; 57(8): 3698-707, 2016 Jul 01.
Article
em En
| MEDLINE
| ID: mdl-27403998
ABSTRACT
PURPOSE:
Elevated intraocular pressure (IOP) in primary open-angle glaucoma (POAG) results from glaucomatous damage to the trabecular meshwork (TM). The glaucoma-associated factor TGFß2 is increased in aqueous humor and TM of POAG patients. We hypothesize that histone acetylation has a role in dysregulated TGFß2 expression.METHODS:
Protein acetylation was compared between nonglaucomatous TM (NTM) and glaucomatous TM (GTM) cells using Western immunoblotting (WB). Nonglaucomatous TM cells were treated with 10 nM thailandepsin-A (TDP-A), a potent histone deacetylase inhibitor for 4 days. Total and nuclear proteins, RNA, and nuclear protein-DNA complexes were harvested for WB, quantitative PCR (qPCR), and chromatin immunoprecipitation (ChIP) assays, respectively. Paired bovine eyes were perfused with TDP-A versus DMSO, or TDP-A versus TDP-A plus the TGFß pathway inhibitor LY364947 for 5 to 9 days. Intraocular pressure, TM, and perfusate proteins were compared.RESULTS:
We found increased acetylated histone 3 and total protein acetylation in the GTM cells and TDP-A treated NTM cells. Chromatin immunoprecipitation assays showed that TDP-A induced histone hyperacetylation associated with the TGFß2 promoter. This change of acetylation significantly increased TGFß2 mRNA and protein expression in NTM cells. In perfusion-cultured bovine eyes, TDP-A increased TGFß2 in the perfusate as well as elevated IOP. Histologic and immunofluorescent analyses showed increased extracellular matrix and cytoskeletal proteins in the TM of TDP-A treated bovine eyes. Cotreatment with the TGFß pathway inhibitor LY364947 blocked TDP-A-induced ocular hypertension.CONCLUSIONS:
Our results suggest that histone acetylation has an important role in increased expression of the glaucoma-associated factor TGFß2. Histone hyperacetylation may be the initiator of glaucomatous damage to the TM.
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Malha Trabecular
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Glaucoma de Ângulo Aberto
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Epigênese Genética
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Fator de Crescimento Transformador beta2
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Inibidores de Histona Desacetilases
Tipo de estudo:
Risk_factors_studies
Limite:
Animals
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article