Critical Roles for PU.1, GATA1, and GATA2 in the Expression of Human FcεRI on Mast Cells: PU.1 and GATA1 Transactivate FCER1A, and GATA2 Transactivates FCER1A and MS4A2
Critical Roles for PU.1, GATA1, and GATA2 in the Expression of Human FcεRI on Mast Cells: PU.1 and GATA1 Transactivate FCER1A, and GATA2 Transactivates FCER1A and MS4A2
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DOI：
10.4049/jimmunol.1302366
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发表时间：
2014-04-15
影响因子：
4.4
通讯作者：
Nishiyama, Chiharu
中科院分区：
文献类型：
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作者：
Inage, Eisuke;Kasakura, Kazumi;Nishiyama, Chiharu
高亲和力 IgE 受体 Fc epsilon RI 由 α、β 和 γ 链组成，在 IgE 介导的过敏反应中发挥重要作用。在目前的研究中，转录因子PU的参与。研究了人肥大细胞上 Fc epsilon RI 表达中的 Fc epsilon RI 1、GATA1 和 GATA2。针对 PU 的小干扰 RNA (siRNA) 转染。 1、GATA1和GATA2进入人肥大细胞系LAD2，导致细胞表面Fc epsilon RI表达显着下调。 mRNA水平的定量显示PU。 1、GATA1 和 GATA2 siRNA 抑制 a 转录物，而仅 GATA2 siRNA 转染子中 β mRNA 的量减少。相比之下，γ mRNA 水平不受任何敲低的影响。染色质免疫沉淀分析显示存在大量 PU。如图 1 所示，GATA1 和 GATA2 与 FCER1A（编码 Fc epsilon RI α）的启动子区域结合，GATA2 与 MS4A2（编码 Fc epsilon RI beta）的启动子区域结合。荧光素酶测定和 EMSA 显示 GATA2 通过直接结合反式激活 MS4A2 启动子。这些转录因子的敲低也抑制了 IgE 介导的 LAD2 脱粒活性。类似地，所有三种敲低均抑制原代肥大细胞（尤其是 PU）中的 Fc epsilon RI 表达。 1 siRNA 和 GATA2 siRNA，分别靶向 Fc epsilon RI α 和 Fc epsilon RI beta。根据这些结果，我们得出结论：PU。 Fc epsilon RI 1 和 GATA1 通过招募至其启动子参与 Fc epsilon RI α 转录，而 GATA2 正向调节 Fc epsilon RI β 转录。这些转录因子的抑制导致 Fc epsilon RI 表达和 IgE 介导的脱颗粒活性下调。我们的研究结果将有助于开发针对 Fc epsilon RI 介导的过敏性疾病的新治疗方法。
The high-affinity IgE receptor, Fc epsilon RI, which is composed of alpha-, beta-, and gamma-chains, plays an important role in IgE-mediated allergic responses. In the current study, involvement of the transcription factors, PU. 1, GATA1, and GATA2, in the expression of Fc epsilon RI on human mast cells was investigated. Transfection of small interfering RNAs (siRNAs) against PU. 1, GATA1, and GATA2 into the human mast cell line, LAD2, caused significant downregulation of cell surface expression of Fc epsilon RI. Quantification of the mRNA levels revealed that PU. 1, GATA1, and GATA2 siRNAs suppressed the a transcript, whereas the amount of beta mRNA was reduced in only GATA2 siRNA transfectants. In contrast, gamma mRNA levels were not affected by any of the knockdowns. Chromatin immunoprecipitation assay showed that significant amounts of PU. 1, GATA1, and GATA2 bind to the promoter region of FCER1A (encoding Fc epsilon RI alpha) and that GATA2 binds to the promoter of MS4A2 (encoding Fc epsilon RI beta). Luciferase assay and EMSA showed that GATA2 transactivates the MS4A2 promoter via direct binding. These knockdowns of transcription factors also suppressed the IgE-mediated degranulation activity of LAD2. Similarly, all three knockdowns suppressed Fc epsilon RI expression in primary mast cells, especially PU. 1 siRNA and GATA2 siRNA, which target Fc epsilon RI alpha and Fc epsilon RI beta, respectively. From these results, we conclude that PU. 1 and GATA1 are involved in Fc epsilon RI alpha transcription through recruitment to its promoter, whereas GATA2 positively regulates Fc epsilon RI beta transcription. Suppression of these transcription factors leads to downregulation of Fc epsilon RI expression and IgEmediated degranulation activity. Our findings will contribute to the development of new therapeutic approaches for Fc epsilon RI-mediated allergic diseases.