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Proc Natl Acad Sci U S A. 2013 Feb 5;110(6):2228-33. doi: 10.1073/pnas.1222285110. Epub 2013 Jan 23.

Mutation of the ATP-gated P2X(2) receptor leads to progressive hearing loss and increased susceptibility to noise.

Author information

1
Department of Otolaryngology, University of Miami School of Medicine, Miami, FL 33136, USA.

Abstract

Age-related hearing loss and noise-induced hearing loss are major causes of human morbidity. Here we used genetics and functional studies to show that a shared cause of these disorders may be loss of function of the ATP-gated P2X(2) receptor (ligand-gated ion channel, purinergic receptor 2) that is expressed in sensory and supporting cells of the cochlea. Genomic analysis of dominantly inherited, progressive sensorineural hearing loss DFNA41 in a six-generation kindred revealed a rare heterozygous allele, P2RX2 c.178G > T (p.V60L), at chr12:133,196,029, which cosegregated with fully penetrant hearing loss in the index family, and also appeared in a second family with the same phenotype. The mutation was absent from more than 7,000 controls. P2RX2 p.V60L abolishes two hallmark features of P2X(2) receptors: ATP-evoked inward current response and ATP-stimulated macropore permeability, measured as loss of ATP-activated FM1-43 fluorescence labeling. Coexpression of mutant and WT P2X(2) receptor subunits significantly reduced ATP-activated membrane permeability. P2RX2-null mice developed severe progressive hearing loss, and their early exposure to continuous moderate noise led to high-frequency hearing loss as young adults. Similarly, among family members heterozygous for P2RX2 p.V60L, noise exposure exacerbated high-frequency hearing loss in young adulthood. Our results suggest that P2X(2) function is required for life-long normal hearing and for protection from exposure to noise.

PMID:
23345450
PMCID:
PMC3568371
DOI:
10.1073/pnas.1222285110
[Indexed for MEDLINE]
Free PMC Article

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