美国斯克里普斯研究所Michael Farzan和Guocai Zhong合作发现一种可逆性的RNA开关，在体内调控腺相关病毒（AAV）传递基因的表达。这一研究成果在线发表在2019年12月23日的《自然—生物技术》上。

在这项研究中，研究人员对一类III型锤头状核酶进行改造从而产生一种高效的RNA开关，该开关可顺式切割哺乳动物mRNA，并且受到原子空间封闭的反义寡核苷酸调控。该变体核酶能在体内调节AAV传递的基因，并且可以实现剂量依赖性调控蛋白质表达，其提高蛋白质表达可达223倍并至少能维持43周。通过测试这些可逆开关在慢性肾脏贫血症基因治疗的潜力，研究人员发现在剂量耐受范围内诱导寡核苷酸可调节促红细胞生成素的生理水平表达。这些小型、模块化和高效的RNA开关可以提高基因疗法的安全性和有效性，并扩大了其用途。

据了解，基因治疗的广泛使用受到缺少具有可动态调控小型遗传开关元件的限制，该遗传开关控制转基因表达而无需其他蛋白质成分。

附：英文原文

Title: A reversible RNA on-switch that controls gene expression of AAV-delivered therapeutics in vivo

Author: Guocai Zhong, Haimin Wang, Wenhui He, Yujun Li, Huihui Mou, Zachary J. Tickner, Mai H. Tran, Tianling Ou, Yiming Yin, Huitian Diao, Michael Farzan

Issue&Volume: 2019-12-23

Abstract: Widespread use of gene therapy technologies is limited in part by the lack of small genetic switches with wide dynamic ranges that control transgene expression without the requirement of additional protein components1,2,3,4,5. In this study, we engineered a class of type III hammerhead ribozymes to develop RNA switches that are highly efficient at cis-cleaving mammalian mRNAs and showed that they can be tightly regulated by a steric-blocking antisense oligonucleotide. Our variant ribozymes enabled in vivo regulation of adeno-associated virus (AAV)-delivered transgenes, allowing dose-dependent and up to 223-fold regulation of protein expression over at least 43 weeks. To test the potential of these reversible on-switches in gene therapy for anemia of chronic kidney disease6, we demonstrated regulated expression of physiological levels of erythropoietin with a well-tolerated dose of the inducer oligonucleotide. These small, modular and efficient RNA switches may improve the safety and efficacy of gene therapies and broaden their use.

DOI: 10.1038/s41587-019-0357-y

Source: https://www.nature.com/articles/s41587-019-0357-y