美国圣犹达儿童研究医院Jonathan S. Yen，Mitchell J. Weiss和美国哈佛大学David R. Liu共同合作，近期取得重要工作进展。他们通过碱基编辑有效且均匀地诱导胎儿血红蛋白的表达。相关研究成果2023年7月3日在线发表于《自然—遗传学》杂志上。

据介绍，在红细胞中诱导胎儿血红蛋白（HbF）可以缓解β-地中海贫血和镰状细胞病。

研究人员使用Cas9核酸酶或腺嘌呤碱基编辑器比较了CD34⁺造血干细胞和祖细胞中的五种策略。最有效的修饰是腺嘌呤碱基编辑器生成γ-珠蛋白–175A>G。纯合子–175A>G编辑的红系菌落表达81±7%的HbF，未经编辑的对照为17±11%，而针对γ-珠蛋白启动子中的BCL11A结合基序或BCL11A红系增强子的两种Cas9策略中，HbF水平更低且变化更大。在CD34⁺造血干细胞和祖细胞移植到小鼠体内后产生的红细胞中，-175A>G碱基编辑也比Cas9方法更有效地诱导HbF。

总之，这一数据提出了一种有效、均匀诱导HbF的策略，并为γ-珠蛋白基因调控提供了见解。更普遍地说，这一研究证明了Cas9产生的不同indel可以引起意想不到的表型变异，而碱基编辑可以绕过这种变异，更加安全可靠。

附：英文原文

Title: Potent and uniform fetal hemoglobin induction via base editing

Author: Mayuranathan, Thiyagaraj, Newby, Gregory A., Feng, Ruopeng, Yao, Yu, Mayberry, Kalin D., Lazzarotto, Cicera R., Li, Yichao, Levine, Rachel M., Nimmagadda, Nikitha, Dempsey, Erin, Kang, Guolian, Porter, Shaina N., Doerfler, Phillip A., Zhang, Jingjing, Jang, Yoonjeong, Chen, Jingjing, Bell, Henry W., Crossley, Merlin, Bhoopalan, Senthil Velan, Sharma, Akshay, Tisdale, John F., Pruett-Miller, Shondra M., Cheng, Yong, Tsai, Shengdar Q., Liu, David R., Weiss, Mitchell J., Yen, Jonathan S.

Issue&Volume: 2023-07-03

Abstract: Inducing fetal hemoglobin (HbF) in red blood cells can alleviate β-thalassemia and sickle cell disease. We compared five strategies in CD34+ hematopoietic stem and progenitor cells, using either Cas9 nuclease or adenine base editors. The most potent modification was adenine base editor generation of γ-globin –175A>G. Homozygous –175A>G edited erythroid colonies expressed 81±7% HbF versus 17±11% in unedited controls, whereas HbF levels were lower and more variable for two Cas9 strategies targeting a BCL11A binding motif in the γ-globin promoter or a BCL11A erythroid enhancer. The –175A>G base edit also induced HbF more potently than a Cas9 approach in red blood cells generated after transplantation of CD34+ hematopoietic stem and progenitor cells into mice. Our data suggest a strategy for potent, uniform induction of HbF and provide insights into γ-globin gene regulation. More generally, we demonstrate that diverse indels generated by Cas9 can cause unexpected phenotypic variation that can be circumvented by base editing.

DOI: 10.1038/s41588-023-01434-7

Source: https://www.nature.com/articles/s41588-023-01434-7