Hong Seongho, Kim Sol Pin, Kim Sanghun, Kang Soo Kyung, Jung Sungmo, Oh Yeji, Choi Seung Hee, Lee Su Bin, Cha Hou, Kim Jieun, Bae Jiyoung, Park Jiyoon, Kim Kyoungmi, Choi Chang Geun, Park Soo-Ji, Kim Do Hyun, Kim Lark Kyun, Seong Je Kyung, Lee Hyunji
Laboratory of Developmental Biology and Genomics, BK21 PLUS Program for Creative Veterinary Science Research, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea.
Korea Model Animal Priority Center, Seoul National University, Seoul 08826, Republic of Korea.
Mol Ther Nucleic Acids. 2025 Aug 11;36(3):102678. doi: 10.1016/j.omtn.2025.102678. eCollection 2025 Sep 9.
Mitochondrial DNA (mtDNA) base editors are powerful tools for investigating mitochondrial diseases. However, their editing efficiency can vary significantly depending on the target site within the mtDNA. In this study, we developed two improved versions of the mitochondrial adenine base editor (Hifi-sTALED and αnHifi-sTALED) by modifying components other than the TadA8e-V28R deaminase variant. These enhancements significantly increased editing efficiency while preserving minimal off-target effects across the transcriptome. Using these optimized editors, we achieved improved mtDNA editing in mouse embryos and successfully generated mutant mice with high heteroplasmic loads. Functional analyses revealed that the mutation impaired mitochondrial function, as indicated by reduced ATP production and decreased oxygen consumption rate (OCR). These findings demonstrate the utility of the enhanced base editors in generating mitochondrial disease models and advancing research in mitochondrial genetics.
线粒体DNA（mtDNA）碱基编辑器是研究线粒体疾病的强大工具。然而，它们的编辑效率会因mtDNA内的靶位点而有显著差异。在本研究中，我们通过修改除TadA8e-V28R脱氨酶变体之外的组件，开发了线粒体腺嘌呤碱基编辑器的两个改进版本（Hifi-sTALED和αnHifi-sTALED）。这些改进显著提高了编辑效率，同时在整个转录组中保持了最小的脱靶效应。使用这些优化的编辑器，我们在小鼠胚胎中实现了改进的mtDNA编辑，并成功生成了具有高异质性负荷的突变小鼠。功能分析表明，该突变损害了线粒体功能，表现为ATP生成减少和氧消耗率（OCR）降低。这些发现证明了增强型碱基编辑器在生成线粒体疾病模型和推进线粒体遗传学研究方面的效用。
