Hypervulnerability to sound-exposure through impaired adaptive proliferation of peroxisomes
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ABSTRACT: A deficiency of pejvakin, a protein of unknown function, causes a strikingly heterogeneous form of deafness. Pejvakin-deficient (Pjvk-/-) mice also exhibited variable auditory phenotypes. Correlation between their hearing thresholds and the number of pups per cage suggested a possible harmful effect of pup vocalizations. Direct sound or electrical stimulation showed that the cochlear sensory hair cells and auditory pathway neurons of Pjvk-/- mice and patients were exceptionally vulnerable to sound. Pjvk-/- cochleas displayed features of marked oxidative stress and impaired anti-oxidant defenses. We showed that pejvakin is associated with peroxisomes, and is required for the oxidative stress-induced proliferation of these organelles. In Pjvk-/- hair cells, peroxisomes displayed structural abnormalities after the onset of hearing. Noise-exposure of wild-type mice rapidly upregulated Pjvk cochlear transcription, and triggered peroxisome proliferation in hair cells and primary auditory neurons. Our results reveal that the anti-oxidant activity of peroxisomes protects the auditory system against noise-induced damage. Three RNA samples was extracted from dissected organ of Corti (OC) for each genotype (Pjvk-/- and Pjvk+/+ mice) and analyzed (triplicate OCmm-1, OCmm-2, and OCmm-3 for Pjvk-/-, and triplicate OCpp-1, OCpp-2, and OCpp-3 for Pjvk+/+).
ORGANISM(S): Mus musculus
SUBMITTER: Sedigheh Delmaghani
PROVIDER: E-GEOD-72722 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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