Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Peking University, Beijing 100871, China.
Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China.
Nucleic Acids Res. 2023 Jul 21;51(13):6634-6653. doi: 10.1093/nar/gkad468.
Mammalian erythroid development can be divided into three stages: hematopoietic stem and progenitor cell (HSPC), erythroid progenitor (Ery-Pro), and erythroid precursor (Ery-Pre). However, the mechanisms by which the 3D genome changes to establish the stage-specific transcription programs that are critical for erythropoiesis remain unclear. Here, we analyze the chromatin landscape at multiple levels in defined populations from primary human erythroid culture. While compartments and topologically associating domains remain largely unchanged, ∼50% of H3K27Ac-marked enhancers are dynamic in HSPC versus Ery-Pre. The enhancer anchors of enhancer-promoter loops are enriched for occupancy of respective stage-specific transcription factors (TFs), indicating these TFs orchestrate the enhancer connectome rewiring. The master TF of erythropoiesis, GATA1, is found to occupy most erythroid gene promoters at the Ery-Pro stage, and mediate conspicuous local rewiring through acquiring binding at the distal regions in Ery-Pre, promoting productive erythroid transcription output. Knocking out GATA1 binding sites precisely abrogates local rewiring and corresponding gene expression. Interestingly, knocking down GATA1 can transiently revert the cell state to an earlier stage and prolong the window of progenitor state. This study reveals mechanistic insights underlying chromatin rearrangements during development by integrating multidimensional chromatin landscape analyses to associate with transcription output and cellular states.
造血干细胞和祖细胞(HSPC)、红细胞祖细胞(Ery-Pro)和红细胞前体细胞(Ery-Pre)。然而,对于 3D 基因组如何发生变化以建立对红细胞生成至关重要的特定于阶段的转录程序的机制仍不清楚。在这里,我们分析了来自原代人红细胞培养的多个定义群体的多个层次的染色质景观。虽然隔室和拓扑关联域基本保持不变,但在 HSPC 与 Ery-Pre 相比,约 50%的 H3K27Ac 标记的增强子是动态的。增强子-启动子环的增强子锚点富含各自阶段特异性转录因子(TF)的占据,表明这些 TF 协调增强子连接网络的重新布线。红细胞生成的主 TF,GATA1,在 Ery-Pro 阶段被发现占据大多数红细胞基因的启动子,并且通过在 Ery-Pre 中的远端区域获得结合来介导明显的局部重新布线,从而促进有生产力的红细胞转录输出。敲除 GATA1 结合位点可精确地阻断局部重布线和相应的基因表达。有趣的是,敲低 GATA1 可以短暂地将细胞状态逆转到更早的阶段,并延长祖细胞状态的窗口。这项研究通过整合多维染色质景观分析来关联转录输出和细胞状态,揭示了发育过程中染色质重排的机制见解。