Disabling hearing loss impacts ∼466 million individuals worldwide with 34 million children affected. Gene and pharmacotherapeutic strategies to rescue auditory function in mouse models of human deafness are most effective when administered before hearing onset, after which therapeutic efficacy is significantly diminished or lost. We hypothesize that preemptive correction of a mutation in the fetal inner ear prior to maturation of the sensory epithelium will optimally restore sensory function. We previously demonstrated that transuterine microinjection of a splice-switching antisense oligonucleotide (ASO) into the amniotic cavity immediately surrounding the embryo on embryonic day 13-13.5 (E13-13.5) corrected pre-mRNA splicing in the juvenile Usher syndrome type 1c (Ush1c) mouse mutant. Here, we show that this strategy only marginally rescues hearing and partially rescues vestibular function. To improve therapeutic outcomes, we microinjected ASO directly into the E12.5 inner ear. A single intra-otic dose of ASO corrects harmonin RNA splicing, restores harmonin protein expression in sensory hair cell bundles, prevents hair cell loss, improves hearing sensitivity, and ameliorates vestibular dysfunction. Improvements in auditory and vestibular function were sustained well into adulthood. Our results demonstrate that an ASO pharmacotherapeutic administered to a developing organ system in utero preemptively corrects pre-mRNA splicing to abrogate the disease phenotype.

中文翻译：

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胎儿反义寡核苷酸治疗先天性耳聋和前庭功能障碍。


残疾性听力损失影响着全球约 4.66 亿人，其中有 3400 万儿童受到影响。拯救人类耳聋小鼠模型听觉功能的基因和药物治疗策略在听力出现之前施用时最为有效，之后治疗效果会显着减弱或丧失。我们假设，在感觉上皮成熟之前先发制人地纠正胎儿内耳的突变将最好地恢复感觉功能。我们之前证明，在胚胎第 13-13.5 天 (E13-13.5) 将剪接转换反义寡核苷酸 (ASO) 经子宫显微注射到紧邻胚胎周围的羊膜腔中，可以纠正 1c 型青少年亚瑟综合征 (Ush1c) 中的前 mRNA 剪接小鼠突变体。在这里，我们表明这种策略只能略微挽救听力并部分挽救前庭功能。为了改善治疗效果，我们将 ASO 直接显微注射到 E12.5 内耳中。单次耳内剂量的 ASO 可纠正 Harmonin RNA 剪接，恢复感觉毛细胞束中 Harmonin 蛋白的表达，防止毛细胞损失，提高听力灵敏度，并改善前庭功能障碍。听觉和前庭功能的改善一直持续到成年期。我们的结果表明，对子宫内发育中的器官系统施用 ASO 药物治疗可以先发制人地纠正前 mRNA 剪接，从而消除疾病表型。