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- Bademci, Guney, et al.
(author)
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FOXF2 is required for cochlear development in humans and mice.
- 2019
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In: Human molecular genetics. - : Oxford University Press (OUP). - 1460-2083 .- 0964-6906. ; 28:8, s. 1286-1297
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Journal article (peer-reviewed)abstract
- Molecular mechanisms governing the development of the human cochlea remain largely unknown. Through genome sequencing, we identified a homozygous FOXF2 variant c.325A>T (p.I109F) in a child with profound sensorineural hearing loss associated with incomplete partition type I anomaly of the cochlea. This variant is not found in public databases or in over 1,000 ethnicity-matched control individuals. I109 is a highly conserved residue in the forkhead box (Fox) domain of FOXF2, a member of the Fox protein family of transcription factors that regulate the expression of genes involved in embryogenic development as well as adult life. Our in vitro studies show that the half-life of mutant FOXF2 is reduced compared to that of wildtype. Foxf2 is expressed in the cochlea of developing and adult mice. The mouse knockout of Foxf2 shows shortened and malformed cochleae, in addition to altered shape of hair cells with innervation and planar cell polarity defects. Expressions of Eya1 and Pax3, genes essential for cochlear development, are reduced in the cochleae of Foxf2 knockout mice. We conclude that FOXF2 plays a major role in cochlear development and its dysfunction leads to sensorineural hearing loss and developmental anomalies of the cochlea in humans and mice.
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| 2. |
- Prasad, Sonal, 1988-, et al.
(author)
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Radixin modulates the function of outer hair cell stereocilia
- 2020
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In: Communications Biology. - : Nature Research. - 2399-3642. ; 3:1
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Journal article (peer-reviewed)abstract
- The stereocilia of the inner ear sensory cells contain the actin-binding protein radixin, encoded by RDX. Radixin is important for hearing but remains functionally obscure. To determine how radixin influences hearing sensitivity, we used a custom rapid imaging technique to visualize stereocilia motion while measuring electrical potential amplitudes during acoustic stimulation. Radixin inhibition decreased sound-evoked electrical potentials. Other functional measures, including electrically induced sensory cell motility and sound-evoked stereocilia deflections, showed a minor amplitude increase. These unique functional alterations demonstrate radixin as necessary for conversion of sound into electrical signals at acoustic rates. We identified patients with RDX variants with normal hearing at birth who showed rapidly deteriorating hearing during the first months of life. This may be overlooked by newborn hearing screening and explained by multiple disturbances in postnatal sensory cells. We conclude radixin is necessary for ensuring normal conversion of sound to electrical signals in the inner ear.
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