Gap-junction channels dysfunction in deafness and hearing loss.
Gap-junction channels connect the cytoplasm of adjacent cells, allowing the diffusion of ions and small metabolites. They are formed at the appositional plasma membranes by a family of related proteins named connexins. Mutations in connexins 26, 31, 30, 32, and 43 have been associated with nonsyndromic or syndromic deafness. The majority of these mutations are inherited in an autosomal recessive manner, but a few of them have been associated with dominantly inherited hearing loss. Mutations in the connexin26 gene (GJB2) are the most common cause of genetic deafness. This review summarizes the most relevant and recent information about different mutations in connexin genes found in human patients, with emphasis on GJB2. The possible effects of the mutations on channel expression and function are discussed, in addition to their possible physiologic consequences for inner ear physiology. Finally, we propose that connexin channels (gap junctions and hemichannels) may be targets for age-related hearing loss induced by oxidative damage.
Centro de Neurociencias de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile. agustin.martinez@uv.cl
Agustín D
AD
Martínez
Rodrigo
R
Acuña
Vania
V
Figueroa
Jaime
J
Maripillan
Bruce
B
Nicholson
D000072259:Connexin 26; D017630:Connexins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D003638:Deafness / Q000235:genetics*; D017629:Gap Junctions / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D034381:Hearing Loss / Q000235:genetics*; D006801:Humans
D017630:Connexins; C000607042:GJB2 protein, human; D000072259:Connexin 26