Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
Department of Radiation Oncology and Oncological Sciences, Univ. of Utah School of Medicine and the Huntsman Cancer Institute, Salt Lake City, UT, USA.
Nucleic Acids Res. 2019 Nov 18;47(20):10612-10627. doi: 10.1093/nar/gkz816.
Histone deacetylase 3 (Hdac3) is a target of the FDA approved HDAC inhibitors, which are used for the treatment of lymphoid malignancies. Here, we used Cd19-Cre to conditionally delete Hdac3 to define its role in germinal center B cells, which represent the cell of origin for many B cell malignancies. Cd19-Cre-Hdac3-/- mice showed impaired germinal center formation along with a defect in plasmablast production. Analysis of Hdac3-/- germinal centers revealed a reduction in dark zone centroblasts and accumulation of light zone centrocytes. RNA-seq revealed a significant correlation between genes up-regulated upon Hdac3 loss and those up-regulated in Foxo1-deleted germinal center B cells, even though Foxo1 typically activates transcription. Therefore, to determine whether gene expression changes observed in Hdac3-/- germinal centers were a result of direct effects of Hdac3 deacetylase activity, we used an HDAC3 selective inhibitor and examined nascent transcription in germinal center-derived cell lines. Transcriptional changes upon HDAC3 inhibition were enriched for light zone gene signatures as observed in germinal centers. Further comparison of PRO-seq data with ChIP-seq/exo data for BCL6, SMRT, FOXO1 and H3K27ac identified direct targets of HDAC3 function including CD86, CD83 and CXCR5 that are likely responsible for driving the light zone phenotype observed in vivo.
组蛋白去乙酰化酶 3 (Hdac3) 是美国食品和药物管理局批准的组蛋白去乙酰化酶抑制剂的靶点，这些抑制剂用于治疗淋巴恶性肿瘤。在这里，我们使用 Cd19-Cre 条件性删除 Hdac3，以确定其在生发中心 B 细胞中的作用，生发中心 B 细胞是许多 B 细胞恶性肿瘤的起源细胞。Cd19-Cre-Hdac3-/- 小鼠表现出生发中心形成受损，以及浆母细胞生成缺陷。对 Hdac3-/- 生发中心的分析显示暗区中心母细胞减少，亮区中心细胞积累。RNA-seq 分析显示，在 Hdac3 缺失后上调的基因与 Foxo1 缺失的生发中心 B 细胞中上调的基因之间存在显著相关性，尽管 Foxo1 通常激活转录。因此，为了确定在 Hdac3-/- 生发中心中观察到的基因表达变化是否是 Hdac3 去乙酰化酶活性的直接作用的结果，我们使用了一种 HDAC3 选择性抑制剂，并在生发中心衍生的细胞系中检查了新生转录。HDAC3 抑制后的转录变化富集了生发中心中观察到的亮区基因特征。进一步将 PRO-seq 数据与 BCL6、SMRT、FOXO1 和 H3K27ac 的 ChIP-seq/exo 数据进行比较，确定了 HDAC3 功能的直接靶标，包括 CD86、CD83 和 CXCR5，这些靶标可能负责驱动体内观察到的亮区表型。
