Restoration of mitochondrial function through activation of hypomodified tRNAs with pathogenic mutations associated with mitochondrial diseases.
Restoration of mitochondrial function through activation of hypomodified tRNAs with pathogenic mutations associated with mitochondrial diseases.
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DOI：
10.1093/nar/gkad139
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发表时间：
2023-08-11
影响因子：
14.9
通讯作者：
中科院分区：
文献类型：
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线粒体 (mt-)tRNA 突变经常导致线粒体功能障碍。线粒体肌病、脑病、乳酸性酸中毒和中风样发作 (MELAS) 以及与锯齿状红纤维相关的肌阵挛癫痫 (MERRF) 是线粒体疾病的主要临床亚组，由 mtDNA 编码的 tRNA 基因的致病性点突变引起。我们之前报道了分别从 MELAS 和 MERRF 患者细胞中分离的突变 mt-tRNA 的反密码子中 5-牛磺酸甲基尿苷 (τm5U) 及其 2-硫尿苷衍生物 (τm5s2U) 的频率严重降低。低修饰的 tRNA 无法有效解码同源密码子，导致线粒体中呼吸链蛋白的翻译缺陷。为了恢复 MELAS 患者细胞的线粒体活性，我们在患者来源的成肌细胞中过度表达 MTO1（一种 τm5U 修饰酶）。我们使用了新开发的引物延伸方法，结果表明MTO1过表达几乎完全恢复了MELAS突变体mt-tRNALeu（UUR）的τm5U修饰。线粒体蛋白质合成和耗氧率的增加表明，MELAS患者细胞的线粒体功能可以通过恢复突变tRNA的τm5U来激活。此外，我们证实 MTO1 表达恢复了 MERRF 患者细胞中突变 mt-tRNALys 的 τm5s2U。这些发现为线粒体疾病的表观转录组疗法铺平了道路。
Mutations in mitochondrial (mt-)tRNAs frequently cause mitochondrial dysfunction. Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS), and myoclonus epilepsy associated with ragged red fibers (MERRF) are major clinical subgroups of mitochondrial diseases caused by pathogenic point mutations in tRNA genes encoded in mtDNA. We previously reported a severe reduction in the frequency of 5-taurinomethyluridine (τm5U) and its 2-thiouridine derivative (τm5s2U) in the anticodons of mutant mt-tRNAs isolated from the cells of patients with MELAS and MERRF, respectively. The hypomodified tRNAs fail to decode cognate codons efficiently, resulting in defective translation of respiratory chain proteins in mitochondria. To restore the mitochondrial activity of MELAS patient cells, we overexpressed MTO1, a τm5U-modifying enzyme, in patient-derived myoblasts. We used a newly developed primer extension method and showed that MTO1 overexpression almost completely restored the τm5U modification of the MELAS mutant mt-tRNALeu(UUR). An increase in mitochondrial protein synthesis and oxygen consumption rate suggested that the mitochondrial function of MELAS patient cells can be activated by restoring the τm5U of the mutant tRNA. In addition, we confirmed that MTO1 expression restored the τm5s2U of the mutant mt-tRNALys in MERRF patient cells. These findings pave the way for epitranscriptomic therapies for mitochondrial diseases.
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影响因子：
3.9
作者：
Baruffini, Enrico;Dallabona, Cristina;Invernizzi, Federica;Yarham, John W.;Melchionda, Laura;Blakely, Emma L.;Lamantea, Eleonora;Donnini, Claudia;Santra, Saikat;Vijayaraghavan, Suresh;Roper, Helen P.;Burlina, Alberto;Kopajtich, Robert;Walther, Anett;Strom, Tim M.;Haack, Tobias B.;Prokisch, Holger;Taylor, Robert W.;Ferrero, Ileana;Zeviani, Massimo;Ghezzi, Daniele
通讯作者：
Ghezzi, Daniele
影响因子：
64.8
作者：
GOTO, Y;NONAKA, I;HORAI, S
通讯作者：
HORAI, S
影响因子：
9.9
作者：
GOTO, Y;HORAI, S;NONAKA, I
通讯作者：
NONAKA, I
影响因子：
5.4
作者：
Dull, T;Zufferey, R;Naldini, L
通讯作者：
Naldini, L
影响因子：
82.9
作者：
通讯作者：
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