Restoration of connexin26 protein level in the cochlea completely rescues hearing in a mouse model of human connexin30-linked deafness.
Mutations in genes coding for connexin26 (Cx26) and/or Cx30 are linked to approximately half of all cases of human autosomal nonsyndromic prelingual deafness. Cx26 and Cx30 are the two major Cx isoforms found in the cochlea, and they coassemble to form hybrid (heteromeric and heterotypic) gap junctions (GJs). This molecular arrangement implies that homomeric GJs would remain in the cochlea if one of the coassembly partners were mutated resulting in null expression. We generated mice in which extra copies of the Cx26 gene were transgenically expressed from a modified bacterial artificial chromosome in a Cx30-/- background. In the absence of the Cx30 gene, Cx26 expressed from extra alleles completely restored hearing sensitivity and prevented hair cell death in deaf Cx30-/- mice. The results indicated that hybrid GJs consisting of Cx26 and Cx30 were not essential for normal hearing in mice and suggested that up-regulation of Cx26 or slowing down its protein degradation might be a therapeutic strategy to prevent and treat deafness caused by Cx30 mutations.
Ahmad
Shoeb
S
Department of Otolaryngology, Yerkes Microarray Core, Emory University School of Medicine, 615 Michael Street, Atlanta, GA 30322-3030, USA.
Tang
Wenxue
W
Chang
Qing
Q
Qu
Yan
Y
Hibshman
Jill
J
Li
Yuhua
Y
Söhl
Goran
G
Willecke
Klaus
K
Chen
Ping
P
Lin
Xi
X
D000818:Animals; D015139:Blotting, Southern; D015153:Blotting, Western; D016923:Cell Death; D003051:Cochlea / Q000378:metabolism*; D000072259:Connexin 26; D000075302:Connexin 30; D017630:Connexins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D003638:Deafness / Q000235:genetics / Q000628:therapy*; D004195:Disease Models, Animal; D015870:Gene Expression; D006198:Hair Cells, Auditory / Q000473:pathology; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D016133:Polymerase Chain Reaction
D000075302:Connexin 30; D017630:Connexins; C000607042:GJB2 protein, human; C100629:Gjb6 protein, mouse; D000072259:Connexin 26