Oculopharyngeal muscular dystrophy (OPMD) is caused by a small expansion of a short polyalanine (polyAla) tract in the poly(A)-binding protein nuclear 1 protein (PABPN1). Despite the monogenic nature of OPMD, no treatment is currently available. Here we report an RNA replacement strategy that has therapeutic potential in cell and C. elegans OPMD models. We develop selective microRNAs (miRNAs) against PABPN1, and we report that miRNAs and our previously developed hammerhead ribozymes (hhRzs) are capable of reducing the expression of both the mRNA and protein levels of PABPN1 by as much as 90%. Since OPMD derives from a very small expansion of GCG within the polyAla tract, our hhRz and miRNA molecules cannot distinguish between the wild-type and mutant mRNAs of PABPN1. Therefore, we designed an optimized-codon wild-type PABPN1 (opt-PABPN1) that is resistant to cleavage by hhRzs and miRNAs. Co-expression of opt-PABPN1 with either our hhRzs or miRNAs restored the level of PABPN1, concomitantly with a reduction in expanded PABPN1-associated cell death in a stable C2C12 OPMD model. Interestingly, knockdown of the PABPN1 by selective hhRzs in the C. elegans OPMD model significantly improved the motility of the PABPN1-13Ala worms. Taken together, RNA replacement therapy represents an exciting approach for OPMD treatment.

眼咽肌营养不良症（OPMD）是由短的聚丙氨酸（polyAla）束在poly（A）结合蛋白核1蛋白（PABPN1）中的小膨胀引起的。尽管OPMD具有单基因性质，但目前尚无治疗方法。在这里，我们报告了一种在细胞和秀丽隐杆线虫OPMD模型中具有治疗潜力的RNA替代策略。我们开发针对PABPN1选择性微RNA（miRNA），和我们报告说，miRNA和我们先前开发的锤头状核酶（hhRzs）能够减少的mRNA和蛋白水平的表达PABPN1多达90％。由于来自GCG的polyAla道内的非常小的膨胀OPMD导出，我们hhRz和miRNA分子不能与野生型和突变体的mRNA区分PABPN1。因此，我们设计了一种优化的密码子野生型PABPN1（opt-PABPN1），可抵抗hhRzs和miRNA的切割。在稳定的C2C12 OPMD模型中，与我们的hhRzs或miRNA共同表达opt-PABPN1可恢复PABPN1的水平，同时减少与扩展的PABPN1相关的细胞死亡。有趣的是，在秀丽隐杆线虫OPMD模型中通过选择性hhRzs敲除PABPN1显着提高了PABPN1-13Ala蠕虫的蠕动能力。综上所述，RNA替代疗法代表了OPMD治疗的令人兴奋的方法。