小柯机器人

德国汉堡大学Zoya Ignatova等研究人员合作发现，工程化的tRNA可抑制细胞和体内的无义突变。2023年5月31日，《自然》杂志在线发表了这项成果。

研究人员介绍了一种基于改变原生tRNA为高效抑制tRNA（sup-tRNA）的策略，通过对其序列进行单独微调，进而适应其携带的氨基酸的物理化学特性。小鼠静脉注射和气管内脂质纳米颗粒（LNP）给药后，恢复了无义突变的功能性蛋白质的生产。通过核糖体分析，LNP-sup-tRNA制剂在内源性原生终止密码子处没有引起明显的阅读突破。对于在临床上重要的囊性纤维化跨膜传导调节器基因（CFTR）的过早终止密码子（PTC），sup-tRNA在细胞系统和病人来源的鼻上皮中重新建立了表达和功能，并恢复了气道容积平衡。这些结果为开发基于tRNA的疗法提供了一个框架，该疗法具有较高的分子安全性和靶向抑制PTC的高疗效。

据了解，无义突变是所有遗传性基因疾病中约11%的根本原因。无义突变将被tRNA解码的有义密码子转换成PTC，导致翻译的突然终止。抑制无义突变的一个策略是使用具有改变的反密码子的天然tRNA与新出现的PTC进行碱基配对，促进翻译。然而，基于tRNA的基因治疗并没有产生临床疗效和安全性的最佳组合，目前还没有针对无义突变个体的治疗方法。

附：英文原文

Title: Engineered tRNAs suppress nonsense mutations in cells and in vivo

Author: Albers, Suki, Allen, Elizabeth C., Bharti, Nikhil, Davyt, Marcos, Joshi, Disha, Perez-Garcia, Carlos G., Santos, Leonardo, Mukthavaram, Rajesh, Delgado-Toscano, Miguel Angel, Molina, Brandon, Kuakini, Kristen, Alayyoubi, Maher, Park, Kyoung-Joo Jenny, Acharya, Grishma, Gonzalez, Jose A., Sagi, Amit, Birket, Susan E., Tearney, Guillermo J., Rowe, Steven M., Manfredi, Candela, Hong, Jeong S., Tachikawa, Kiyoshi, Karmali, Priya, Matsuda, Daiki, Sorscher, Eric J., Chivukula, Pad, Ignatova, Zoya

Issue&Volume: 2023-05-31

Abstract: Nonsense mutations are the underlying cause of approximately 11% of all inherited genetic diseases1. Nonsense mutations convert a sense codon that is decoded by tRNA into a premature termination codon (PTC), resulting in an abrupt termination of translation. One strategy to suppress nonsense mutations is to use natural tRNAs with altered anticodons to base-pair to the newly emerged PTC and promote translation2,3,4,5,6,7. However, tRNA-based gene therapy has not yielded an optimal combination of clinical efficacy and safety and there is presently no treatment for individuals with nonsense mutations. Here we introduce a strategy based on altering native tRNAs into  efficient suppressor tRNAs (sup-tRNAs) by individually fine-tuning their sequence to the physico-chemical properties of the amino acid that they carry. Intravenous and intratracheal lipid nanoparticle (LNP) administration of sup-tRNA in mice restored the production of functional proteins with nonsense mutations. LNP–sup-tRNA formulations caused no discernible readthrough at endogenous native stop codons, as determined by ribosome profiling. At clinically important PTCs in the cystic fibrosis transmembrane conductance regulator gene (CFTR), the sup-tRNAs re-established expression and function in cell systems and patient-derived nasal epithelia and restored airway volume homeostasis. These results provide a framework for the development of tRNA-based therapies with a high molecular safety profile and high efficacy in targeted PTC suppression.

DOI: 10.1038/s41586-023-06133-1

Source: https://www.nature.com/articles/s41586-023-06133-1

Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504
官方网址：http://www.nature.com/
投稿链接：http://www.nature.com/authors/submit_manuscript.html