Brain Korea 21 Project for Biomedical Science, College of Medicine, Korea University, Seoul, Korea.
Clin Exp Allergy. 2012 Jun;42(6):872-82. doi: 10.1111/j.1365-2222.2011.03931.x.
Nasal polyposis is a multi-factorial disease associated with chronic inflammatory condition of the paranasal sinuses. Myofibroblast differentiation and extracellular matrix (ECM) accumulation are involved in the pathogenesis of nasal polyposis.
The aim of this study was to study the effect of trichostatin A (TSA), a histone deacetylase (HDAC) inhibitor, on transforming growth factor (TGF)-β1-induced myofibroblast differentiation and ECM accumulation in nasal polyp-derived fibroblasts (NPDFs).
Nasal polyp-derived fibroblasts were isolated from nasal polyps of patients who have chronic rhinosinusitis with nasal polyp. TSA was treated in TGF-β1-induced NPDFs. Expression levels of HDAC2, α-smooth muscle actin (SMA), TGF-β1, collagen type I, acetylated Histone H3, acetylated Histone H4, phosphorylated Smad2/3 and Smad7 were determined by RT-PCR, western blot and/or immunofluorescent staining. The total collagen amount production was analysed by Sircol soluble collagen assay and contractile activity was measured by collagen gel contraction assay. HDAC2 inhibition by TSA or HDAC2 silencing was established by RT-PCR and western blot. The epigenetic effect on α-SMA gene inactivation was examined by chromatin immunoprecipitation assay. Proliferation was determined by Ki67-positive cell staining and cytotoxicity was assessed by 3-(4,5- dimethylthiazol-2yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay.
The expression levels of HDAC2, α-SMA and TGF-β1 were increased in nasal polyp tissues compared to normal inferior turbinate tissues. TSA and HDAC2 silencing inhibited expression levels α-SMA, collagen and HDAC2. TSA induced hyperacetylation of histone and suppressed opening of α-SMA gene promoter in TGF-β1-induced NPDFs. TSA inhibited TGF-β1-induced Smad 2/3 and rescued TGF-β1-suppressed Smad7 signalling pathway. Finally, TSA blocked proliferation in TGF-β1-induced NPDFs and has no cytotoxic effect in NPDFs.
These results suggest that HDAC inhibition is associated with myofibroblast differentiation and extracelluar matrix accumulation in nasal polyposis. TSA may be useful as an inhibitor of nasal polyp growth, and thus has potential to be used as a novel treatment option for nasal polyposis.
鼻息肉是一种与鼻窦慢性炎症有关的多因素疾病。成纤维细胞向肌成纤维细胞分化和细胞外基质（ECM）的积累参与了鼻息肉的发病机制。
本研究旨在研究组蛋白去乙酰化酶（HDAC）抑制剂曲古抑菌素 A（TSA）对转化生长因子（TGF）-β1诱导的鼻息肉衍生成纤维细胞（NPDF）中肌成纤维细胞分化和细胞外基质积累的影响。
从患有慢性鼻-鼻窦炎伴鼻息肉的患者的鼻息肉中分离鼻息肉衍生的成纤维细胞。在 TGF-β1 诱导的 NPDF 中用 TSA 处理。通过 RT-PCR、western blot 和/或免疫荧光染色检测 HDAC2、α-平滑肌肌动蛋白（SMA）、TGF-β1、胶原 I、乙酰化组蛋白 H3、乙酰化组蛋白 H4、磷酸化 Smad2/3 和 Smad7 的表达水平。通过 Sircol 可溶性胶原测定法分析总胶原产生量，通过胶原凝胶收缩测定法测量收缩活性。通过 RT-PCR 和 western blot 建立 TSA 或 HDAC2 沉默对 HDAC2 的抑制作用。通过染色质免疫沉淀测定法检查对 α-SMA 基因失活的表观遗传作用。通过 Ki67 阳性细胞染色测定增殖，通过 3-(4,5-二甲基噻唑-2-基)-2,5-二苯基-2H-四唑溴盐（MTT）测定法评估细胞毒性。
与正常下鼻甲组织相比，鼻息肉组织中 HDAC2、α-SMA 和 TGF-β1 的表达水平增加。TSA 和 HDAC2 沉默抑制了 α-SMA、胶原和 HDAC2 的表达水平。TSA 诱导组蛋白超乙酰化，并抑制 TGF-β1 诱导的 NPDF 中 α-SMA 基因启动子的开放。TSA 抑制 TGF-β1 诱导的 Smad2/3，并挽救 TGF-β1 抑制的 Smad7 信号通路。最后，TSA 阻断了 TGF-β1 诱导的 NPDF 中的增殖，并且对 NPDF 没有细胞毒性作用。
这些结果表明，HDAC 抑制与鼻息肉中的肌成纤维细胞分化和细胞外基质积累有关。TSA 可用作鼻息肉生长的抑制剂，因此具有作为鼻息肉治疗的新选择的潜力。
