PUBLICATION

Zebrafish in-vivo study reveals deleterious activity of human TBC1D24 genetic variants linked with autosomal dominant hearing loss

Authors
Sarosiak, A., J?drychowska, J., Ozi?b?o, D., Gan, N.S., Ba?dyga, N., Leja, M.L., W?gierski, T., Cruz, I.A., Raible, D.W., Skar?y?ski, H., Tylzanowski, P., Korzh, V., O?dak, M.
ID
ZDB-PUB-241127-9
Date
2024
Source
Biochimica et biophysica acta. Molecular basis of disease   1871(2): 167598 (Journal)
Registered Authors
J?drychowska, Justyna, Korzh, Vladimir, Raible, David, Wegierski, Tomasz
Keywords
Genetic variants, Hearing loss, Pathogenicity, TBC1D24, Zebrafish
MeSH Terms
  • Zebrafish*/genetics
  • Humans
  • Zebrafish Proteins/genetics
  • Zebrafish Proteins/metabolism
  • Mutation
  • Disease Models, Animal
  • Animals
  • GTPase-Activating Proteins*/genetics
  • GTPase-Activating Proteins*/metabolism
  • Hearing Loss/genetics
PubMed
39586506 Full text @ BBA Molecular Basis of Disease
Abstract
Hearing loss is a common sensory impairment with a heterogeneous genetic etiology. Genetic variants in the TBC1D24 gene have recently emerged as an important cause of the non-syndromic autosomal dominant hearing loss (ADHL). However, the molecular mechanism behind the TBC1D24-associated ADHL is unknown. Using a zebrafish model, we investigated involvement of TBC1D24 in hearing and the functional effects of the associated ADHL-causing genetic variants. We show that the morpholino-mediated knockdown of Tbc1d24 resulted in defective ear kinocilia structure and reduced locomotor activity of the embryos. The observed phenotypes were rescued by a wild-type TBC1D24 mRNA but not by a mutant mRNA carrying the ADHL-causing variant c.553G > A (p.Asp185Asn), supporting its pathogenic potential. CRISPR-Cas9-mediated knock-out of tbc1d24 led to mechanosensory deficiency of lateral line neuromasts. Overexpression of TBC1D24 mRNA resulted in developmental abnormalities associated with ciliary dysfunction and mesendodermal mispatterning. We observed that the ADHL-causing TBC1D24 variants: c.553G > A (p.Asp185Asn); c.1460A>T (p.His487Leu), c.1461C > G (p.His487Gln) or a novel variant c.905 T > G (p.Leu302Arg) alleviated the effect of overexpression, indicating that these variants disrupt the TBC1D24 function. Furthermore, the zebrafish phenotypes correspond to the severity of ADHL. Specific changes in ear structures upon TBC1D24 overexpression further highlighted its tissue-specific role in ciliary function and inner ear development. Our findings provide functional evidence for the pathogenic potential of the ADHL-causing TBC1D24 variants and lead to new insights into the function of TBC1D24 in cilia morphogenesis.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping