线粒体单双型突变通过恢复 3243A > G 突变的tRNA 中 taurine 修饰来缓解 MELAS 的呼吸缺陷
Saori Ueda1, Mikako Yagi1,2, Ena Tomoda3
1Department of Clinical Chemistry and Laboratory Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
Nucleic acids research
|July 13, 2023
概括
3243A>G线粒体DNA突变损害了蛋白质合成. 发现第二个突变,3290T>C,可以恢复线粒体功能,并抑制3243A>G突变患者的疾病症状.
科学领域:
- 线粒体遗传学和分子生物学
- 人类遗传学和遗传性疾病
背景情况:
- 线粒体DNA (mtDNA) 中的3243A>G突变是线粒体疾病的常见原因,导致线粒体蛋白质合成受损,这是由于突变mt-tRNALeu (UUR) 的减少5-taurinomethyluridine (τm5U) 修饰导致的.
- 周围血液中3243A>G突变的异质体水平通常会随着年龄的增长而下降.
研究的目的:
- 为了研究3290T>C哈普洛型突变对3243A>G突变患者线粒体功能的影响.
- 探索3290T>C突变作为线粒体疾病中呼吸系统缺陷的治疗抑制剂的潜力.
主要方法:
- 来自携带3243A>G和3290T>C突变的患者生成的cybrid细胞.
- 评估线粒体功能,包括线粒体翻译,呼吸链复合体形成和氧气消耗率.
- 在mt-tRNALeu(UUR) 中测量了tm5U修饰水平,使用化学衍生物的原料延伸方法.
主要成果:
- 三名3243A>G突变水平高 (>90%) 的病例表现出轻微的呼吸系统症状,与3290T>C单元型突变存在相关.
- 3290T>C突变显著改善了线粒体翻译,呼吸链复合体形成和3243A>G突变细胞的氧气消耗.
- 携带3243A>G突变的mt-tRNALeu(UUR) 中tm5U的低修饰被同时发生的3290T>C突变恢复.
结论:
- 3290T>C突变在与3243A>G突变相关的线粒体疾病中起到抑制呼吸系统缺陷的作用.
- 通过3290T>C单基突变恢复tm5U修饰,为与mt-tRNA突变相关的线粒体疾病提供了潜在的治疗策略.
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