Han Areum, Yermalovich Alena, Najia Mohamad Ali T, Pearson Daniel S, Fujiwara Yuko, Bolgov Michael, Kubaczka Caroline, North Trista E, Lundin Vanessa, Orkin Stuart, Daley George Q
Division of Hematology/Oncology, Boston Children's Hospital, Boston, MA, USA.
Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA.
Res Sq. 2025 Apr 24:rs.3.rs-6355281. doi: 10.21203/rs.3.rs-6355281/v1.
Selective RNA degradation during terminal erythropoiesis results in a globin-rich transcriptome in mature erythrocytes, but the specific RNA decay pathways remain unknown. We found that deficiency of the terminal uridylyl transferase enzyme Zcchc6 and the 3'-5' exoribonuclease Dis3l2 in mouse models led to fetal and perinatal reticulocytosis, an accumulation of RNA-rich precursors of terminal erythroid cells, suggesting their crucial roles in terminal red cell differentiation. Notably, knockout embryos exhibited persistent high-level expression of globin, the ortholog of human fetal globin. Perturbation of the Zcchc6-Dis3l2 pathway in mice engineered to express the human b-globin locus likewise increased -globin levels in fetal erythroid cells, suggesting that globin switching entails post-transcriptional mechanisms of mRNA destabilization in addition to transcriptional down-regulation. We cultured human hematopoietic stem and progenitor cells (HSPCs), performed CRISPR/Cas9-mediated knockout of ZCCHC6 and DIS3L2, and observed accumulation of RNA and elevated γ-globin levels in terminal erythroid cells. Our findings reveal a conserved role for the ZCCHC6/DIS3L2 RNA editors in terminal erythropoiesis and demonstrate a post-transcriptional mechanism for globin gene switching, advancing research into erythrocyte generation and globin stabilization to ameliorate hemoglobinopathies.
终末红细胞生成过程中的选择性RNA降解导致成熟红细胞中富含珠蛋白的转录组，但具体的RNA衰变途径仍不清楚。我们发现，在小鼠模型中，终末尿苷酰转移酶Zcchc6和3'-5'外切核糖核酸酶Dis3l2的缺陷导致胎儿和围产期网织红细胞增多，这是终末红细胞前体中富含RNA的细胞积累，表明它们在终末红细胞分化中起关键作用。值得注意的是，基因敲除胚胎表现出人类胎儿珠蛋白直系同源物珠蛋白的持续高水平表达。在经过基因工程改造以表达人类β-珠蛋白基因座的小鼠中，Zcchc6-Dis3l2途径的扰动同样增加了胎儿红细胞中β-珠蛋白的水平，这表明珠蛋白转换除了转录下调外，还涉及mRNA不稳定的转录后机制。我们培养了人类造血干细胞和祖细胞（HSPCs），进行了CRISPR/Cas9介导的ZCCHC6和DIS3L2基因敲除，并观察到终末红细胞中RNA的积累和γ-珠蛋白水平的升高。我们的研究结果揭示了ZCCHC6/DIS3L2 RNA编辑在终末红细胞生成中的保守作用，并证明了珠蛋白基因转换的转录后机制，推动了对红细胞生成和珠蛋白稳定化的研究，以改善血红蛋白病。
