Rescue of mis-splicing of a common SLC26A4 mutant associated with sensorineural hearing loss by antisense oligonucleotides

Pengchao Feng; Zhijiao Xu; Jialin Chen; Meizhen Liu; Yu Zhao; Daqi Wang; Lei Han; Li Wang; Bo Wan; Xingshun Xu; Dali Li; Yilai Shu; Yimin Hua

doi:10.1016/j.omtn.2022.03.015

Rescue of mis-splicing of a common SLC26A4 mutant associated with sensorineural hearing loss by antisense oligonucleotides

Mol Ther Nucleic Acids. 2022 Mar 19:28:280-292. doi: 10.1016/j.omtn.2022.03.015. eCollection 2022 Jun 14.

Authors

Pengchao Feng^{1

2}, Zhijiao Xu^{3

4

5}, Jialin Chen^{1

2}, Meizhen Liu⁶, Yu Zhao^{3

4

5}, Daqi Wang^{3

4

5}, Lei Han^{3

4

5

6

7}, Li Wang⁸, Bo Wan^{1

2}, Xingshun Xu^{1

2}, Dali Li⁶, Yilai Shu^{3

4

5}, Yimin Hua⁸

Affiliations

¹ Department of Neurology and Suzhou Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, 1055 Sanxiang Road, Suzhou 215004, China.
² Institute of Neuroscience, Soochow University, 199 Renai Road, Suzhou, Jiangsu 215123, China.
³ ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai 200031, China.
⁴ Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China.
⁵ NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai 200032, China.
⁶ Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai 200241, China.
⁷ Department of Otorhinolaryngology, The Second Affiliated Hospital, University of South China, Hengyang 421001, China.
⁸ Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China.

Abstract

A wide spectrum of SLC26A4 mutations causes Pendred syndrome and enlarged vestibular aqueduct, both associated with sensorineural hearing loss (SNHL). A splice-site mutation, c.919-2A>G (A-2G), which is common in Asian populations, impairs the 3' splice site of intron 7, resulting in exon 8 skipping during pre-mRNA splicing and a subsequent frameshift that creates a premature termination codon in the following exon. Currently, there is no effective drug treatment for SHNL. For A-2G-triggered SNHL, molecules that correct mis-splicing of the mutant hold promise to treat the disease. Antisense oligonucleotides (ASOs) can promote exon inclusion when targeting specific splicing silencers. Here, we systematically screened a large number of ASOs in a minigene system and identified a few that markedly repressed exon 8 skipping. A lead ASO, which targets a heterogeneous nuclear ribonucleoprotein (hnRNP) A1/A2 intronic splicing silencer (ISS) in intron 8, promoted efficient exon 8 inclusion in cultured peripheral blood mononuclear cells derived from two homozygous patients. In a partially humanized Slc26a4 A-2G mouse model, two subcutaneous injections of the ASO at 160 mg/kg significantly rescued exon 8 splicing in the liver. Our results demonstrate that the ISS-targeting ASO has therapeutic potential to treat genetic hearing loss caused by the A-2G mutation in SLC26A4.

Keywords: MT: Therapies and Applications; SLC26A4; antisense oligonucleotide; c.919-2A>G; hnRNP A1; sensorineural hearing loss; splicing.