Department of Clinical Neuroscience, Centre for Neurodegeneration Research, King’s College London, Institute ofPsychiatry, De Crespigny Park, London, UK.
Hum Mol Genet. 2013 Jul 1;22(13):2603-11. doi: 10.1093/hmg/ddt108. Epub 2013 Mar 3.
Abnormal metabolism of the tau protein is central to the pathogenesis of a number of dementias, including Alzheimer's disease. Aberrant alternative splicing of exon 10 in the tau pre-mRNA resulting in an imbalance of tau isoforms is one of the molecular causes of the inherited tauopathy, FTDP-17. We showed previously in heterologous systems that exon 10 inclusion in tau mRNA could be modulated by spliceosome-mediated RNA trans-splicing (SMaRT). Here, we evaluated the potential of trans-splicing RNA reprogramming to correct tau mis-splicing in differentiated neurons in a mouse model of tau mis-splicing, the htau transgenic mouse line, expressing the human MAPT gene in a null mouse Mapt background. Trans-splicing molecules designed to increase exon 10 inclusion were delivered to neurons using lentiviral vectors. We demonstrate reprogramming of tau transcripts at the RNA level after transduction of cultured neurons or after direct delivery and long-term expression of viral vectors into the brain of htau mice in vivo. Tau RNA trans-splicing resulted in an increase in exon 10 inclusion in the mature tau mRNA. Importantly, we also show that the trans-spliced product is translated into a full-length chimeric tau protein. These results validate the potential of SMaRT to correct tau mis-splicing and provide a framework for its therapeutic application to neurodegenerative conditions linked to aberrant RNA processing.
tau 蛋白的异常代谢是包括阿尔茨海默病在内的多种痴呆症发病机制的核心。tau 前体 mRNA 第 10 外显子的异常选择性剪接导致 tau 同工型失衡，是遗传性 tau 病（FTDP-17）的分子原因之一。我们之前在异源系统中表明，tau mRNA 中的第 10 外显子包含可以通过剪接体介导的 RNA 反式拼接（SMaRT）进行调节。在这里，我们评估了 RNA 反式拼接重编程纠正 tau 异常剪接的潜力，该异常剪接是在 tau 异常剪接的小鼠模型（表达人类 MAPT 基因的 htau 转基因小鼠系）中分化神经元中进行的，该小鼠系在 Mapt 基因缺失的小鼠背景下表达人 MAPT 基因。使用慢病毒载体将设计用于增加第 10 外显子包含的反式拼接分子递送到神经元。我们证明了在培养神经元转导后或在 htau 小鼠体内直接递送和长期表达病毒载体后，tau 转录物在 RNA 水平上进行了重编程。tau RNA 反式拼接导致成熟 tau mRNA 中第 10 外显子包含增加。重要的是，我们还表明，反式拼接产物可翻译为全长嵌合 tau 蛋白。这些结果验证了 SMaRT 纠正 tau 异常剪接的潜力，并为其在与异常 RNA 加工相关的神经退行性疾病中的治疗应用提供了框架。
