TY - JOUR
T1 - Stereocilia defects in the sensory hair cells of the inner ear in mice deficient in integrin α8β1
AU - Evans, Amanda Littlewood
AU - Müller, Ulrich
N1 - Funding Information:
We thank J.M. Bergelson, T. Hasson, R.O. Hynes, J.H. Miner and L.F. Reichardt for reagents; P. Caroni, A. Kralli, D. Monard and P. Mathias for critical reading of the manuscript; members of the laboratory for comments; and T. Laux, P. Piosik and O. Baldomero for technical advice. This work was funded by the Novartis Research Foundation.
PY - 2000/4
Y1 - 2000/4
N2 - The mammalian inner ear contains organs for the detection of sound and acceleration, the cochlea and the vestibule, respectively. Mechanosensory hair cells within the neuroepithelia of these organs transduce mechanical force generated by sound waves or head movements into neuronal signals. Defects in hair cells lead to deafness and balance defects. Hair cells have stereocilia that are indispensable for mechanosensation, but the molecular mechanisms regulating stereocilia formation are poorly understood. We show here that integrin α8β1, its ligand fibronectin and the integrin-regulated focal adhesion kinase (FAK) co-localize to the apical hair-cell surface where stereocilia are forming. In mice homozygous for a targeted mutation of Itga8 (encoding the α8 subunit; ref. 7), this co-localization is perturbed and hair cells in the utricle, a vestibular subcompartment, lack stereocilia or contain malformed stereocilia. Most integrin-α8β1-deficient mice die soon after birth due to kidney defects. Many of the survivors have difficulty balancing, consistent with the structural defects of the inner ear. Our data suggest that integrin α8β1, and potentially other integrins, regulates hair-cell differentiation and stereocilia maturation. Mutations affecting matrix molecules cause inherited forms of inner ear disease and integrins may mediate some effects of matrix molecules in the ear; thus, mutations in integrin genes may lead to inner-ear diseases as well.
AB - The mammalian inner ear contains organs for the detection of sound and acceleration, the cochlea and the vestibule, respectively. Mechanosensory hair cells within the neuroepithelia of these organs transduce mechanical force generated by sound waves or head movements into neuronal signals. Defects in hair cells lead to deafness and balance defects. Hair cells have stereocilia that are indispensable for mechanosensation, but the molecular mechanisms regulating stereocilia formation are poorly understood. We show here that integrin α8β1, its ligand fibronectin and the integrin-regulated focal adhesion kinase (FAK) co-localize to the apical hair-cell surface where stereocilia are forming. In mice homozygous for a targeted mutation of Itga8 (encoding the α8 subunit; ref. 7), this co-localization is perturbed and hair cells in the utricle, a vestibular subcompartment, lack stereocilia or contain malformed stereocilia. Most integrin-α8β1-deficient mice die soon after birth due to kidney defects. Many of the survivors have difficulty balancing, consistent with the structural defects of the inner ear. Our data suggest that integrin α8β1, and potentially other integrins, regulates hair-cell differentiation and stereocilia maturation. Mutations affecting matrix molecules cause inherited forms of inner ear disease and integrins may mediate some effects of matrix molecules in the ear; thus, mutations in integrin genes may lead to inner-ear diseases as well.
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U2 - 10.1038/74286
DO - 10.1038/74286
M3 - Article
C2 - 10742111
AN - SCOPUS:0343673941
VL - 24
SP - 424
EP - 428
JO - Nature Genetics
JF - Nature Genetics
SN - 1061-4036
IS - 4
ER -