HDAC Inhibitor-Mediated Epigenetic Regulation of Glaucoma-Associated TGFβ2 in the Trabecular Meshwork.
HDAC Inhibitor-Mediated Epigenetic Regulation of Glaucoma-Associated TGFβ2 in the Trabecular Meshwork.
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DOI：
10.1167/iovs16-19446
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发表时间：
2016-07-01
影响因子：
4.4
通讯作者：
Mao W
中科院分区：
文献类型：
--
作者：
Bermudez JY;Webber HC;Patel GC;Liu X;Cheng YQ;Clark AF;Mao W
原发性开角型青光眼（POAG）的眼压升高是青光眼对小梁网（TM）的损害所致。青光眼相关因子tgf - β2在POAG患者房水和TM中升高。我们假设组蛋白乙酰化在tgf - β2表达失调中起作用。采用免疫印迹法（WB）比较非青光眼TM （NTM）和青光眼TM （GTM）细胞的蛋白乙酰化程度。用10 nM强效组蛋白去乙酰化酶抑制剂泰国抑郁素- a （TDP-A）处理非腺瘤性TM细胞4天。收集总蛋白和核蛋白、RNA和核蛋白- dna复合物，分别用于WB、定量PCR （qPCR）和染色质免疫沉淀（ChIP）测定。将配对的牛眼分别灌注TDP-A和DMSO，或TDP-A和TDP-A加TGFβ途径抑制剂LY364947 5 - 9天。比较眼内压、TM和灌注蛋白。我们发现在GTM细胞和TDP-A处理的NTM细胞中，乙酰化组蛋白3和总蛋白乙酰化增加。染色质免疫沉淀试验显示，TDP-A诱导与tgf - β2启动子相关的组蛋白超乙酰化。这种乙酰化的改变显著增加了NTM细胞中tgf - β2 mRNA和蛋白的表达。在灌注培养的牛眼中，TDP-A增加了灌注液中的tgf - β2并升高了IOP。组织学和免疫荧光分析显示，TDP-A处理的牛眼TM中细胞外基质和细胞骨架蛋白增加。与TGFβ通路抑制剂LY364947联合治疗可阻断tdp - a诱导的高眼压。我们的研究结果表明，组蛋白乙酰化在青光眼相关因子tgf - β2的表达增加中起重要作用。组蛋白超乙酰化可能是青光眼损害TM的始发因素。
Elevated intraocular pressure (IOP) in primary open-angle glaucoma (POAG) results from glaucomatous damage to the trabecular meshwork (TM). The glaucoma-associated factor TGFβ2 is increased in aqueous humor and TM of POAG patients. We hypothesize that histone acetylation has a role in dysregulated TGFβ2 expression. 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 TGFβ pathway inhibitor LY364947 for 5 to 9 days. Intraocular pressure, TM, and perfusate proteins were compared. 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 TGFβ2 promoter. This change of acetylation significantly increased TGFβ2 mRNA and protein expression in NTM cells. In perfusion-cultured bovine eyes, TDP-A increased TGFβ2 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 TGFβ pathway inhibitor LY364947 blocked TDP-A–induced ocular hypertension. Our results suggest that histone acetylation has an important role in increased expression of the glaucoma-associated factor TGFβ2. Histone hyperacetylation may be the initiator of glaucomatous damage to the TM.