Rational design of a genomically humanized mouse model for dominantly inherited hearing loss, DFNA9

DFNA9 is a dominantly inherited form of adult-onset progressive hearing impairment caused by mutations in the COCH gene. COCH encodes cochlin, a crucial extracellular matrix protein. We established a genomically humanized mouse model for the Dutch/Belgian c.151C>T founder mutation in COCH. Considering upcoming sequence-specific genetic therapies, we exchanged the genomic murine Coch exons 3–6 for the corresponding human sequence. Introducing human-specific genetic information into mouse exons can be risky. To mitigate unforeseen consequences on cochlin function resulting from the introduction of the human COCH protein-coding sequence, we converted all human-specific amino acids to mouse equivalents. We furthermore optimized the recognition of the human COCH exons by the murine splicing machinery during pre-mRNA splicing. Subsequent observations in mouse embryonic stem cells revealed correct splicing of the hybrid Coch transcript. The inner ear of the established humanized Coch mice displays correctly-spliced wild-type and mutant humanized Coch alleles. For a comprehensive study of auditory function, mice were crossbred with C57BL/6 Cdh23753A>G mice to remove the Cdh23ahl allele from the genetic background of the mice. At 9 months, all humanized Coch genotypes showed hearing thresholds comparable to wild-type C57BL/6 Cdh23753A>G mice. This indicates that both the introduction of human wildtype COCH, and correction of Cdh23ahl in the humanized Coch lines was successful. Overall, our approach proved beneficial in eliminating potential adverse events of genomic humanization of mouse genes, and provides us with a model in which sequence-specific therapies directed against the human mutant COCH alle can be investigated. With the hearing and balance defects anticipated to occur late in the second year of life, a long-term follow-up study is ongoing to fully characterize the humanized Coch mouse model.

Language

English

Source (journal)

Hearing research. - Amsterdam

Publication

Amsterdam : 2024

ISSN

0378-5955

DOI

10.1016/J.HEARES.2023.108947

Volume/pages

442 (2024) , p. 1-13

Article Reference

108947

ISI

001164910000001

Pubmed ID

38218018

Full text (Publisher's DOI)

https://doi.org/10.1016/J.HEARES.2023.108947

Full text (open access)

Licensed under a CC BY Attribution license

Faculty/Department				Faculty of Medicine and Health Sciences Faculty of Pharmaceutical, Biomedical and Veterinary Sciences . Biomedical Sciences

Research group				Translational Neurosciences (TNW) Laboratory for Experimental Hematology (LEH) Medical Genetics (MEDGEN)
Project info				Inner ear gene therapy to prevent deafness in DFNA9. Delivery of CRISPR-Cas9 mRNA-based therapy into the inner ear by lipid nanoparticles: Cure deafness by disrupting mutant COCH expression in a humanized DFNA9 mouse model. Development of allele-specific crispr-nuclease gene therapy for late-onset sensorineural hearing impairment in a humanized dfna9 mouse model. Cognition and Auditory-Evoked Potentials in DFNA9 Patients and Humanized Mice - From Normal Function to Adult-Onset Otovestibular Decline The humanized dfna9 mouse model as a novel approach to identify tissue-specific and blood-based bio-assays that reflect human dfna9 pathophysiology and to test crispr/cas systems to prevent hearing loss.
Publication type				A1 Journal article

Subject				Human medicine

Affiliation				Publications with a UAntwerp address

Web of Science

View record in Web of Science®

Identifier

Creation

15.01.2024

Last edited

08.05.2024

To cite this reference

https://hdl.handle.net/10067/2023570151162165141