title: Deafness due to degeneration of cochlear neurons in caspase-3-deficient mice.
abstract: Mice that lack caspase-3, which functions in apoptosis, were generated by gene targeting and shown to undergo hearing loss. The ABR threshold of the caspase-3(-/-) mice was significantly elevated compared to that of caspase-3(+/+) mice at 15 days of age and was progressively elevated further by 30 days. Distortion product otoacoustic emissions were not detectable in caspase-3(-/-) mice at 15 days of age. Caspase-3(-/-) mice exhibited marked degeneration of spiral ganglion neurons and a loss of inner and outer hair cells in the cochlea at 30 days of age, although no such changes were apparent at 15 days. The degenerating neurons manifested features, including cytoplasmic vacuolization, distinct from those characteristic of apoptosis. Spiral ganglion neurons and cochlear hair cells thus appear to require caspase-3 for survival but not for initial development. The mapping of both the human caspase-3 gene and the locus responsible for an autosomal dominant, nonsyndromic form of hearing loss (DFNA24) to chromosome 4q35 suggests that the caspase-3(-/-) mice may represent a model of this human condition.
authors.affiliation: Department of Molecular and Cellular Biology, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Morishita
authors.forename: T
authors.initials: T
authors.lastname: Makishima
authors.forename: C
authors.initials: C
authors.lastname: Kaneko
authors.forename: Y S
authors.initials: YS
authors.lastname: Lee
authors.forename: N
authors.initials: N
authors.lastname: Segil
authors.forename: K
authors.initials: K
authors.lastname: Takahashi
authors.forename: A
authors.initials: A
authors.lastname: Kuraoka
authors.forename: T
authors.initials: T
authors.lastname: Nakagawa
authors.forename: J
authors.initials: J
authors.lastname: Nabekura
authors.forename: K
authors.initials: K
authors.lastname: Nakayama
authors.forename: K I
authors.initials: KI
authors.lastname: Nakayama
mesh_terms: D000375:Aging / Q000473:pathology; D000818:Animals; D001309:Auditory Threshold; D053148:Caspase 3; D020169:Caspases / Q000096:biosynthesis / Q000172:deficiency* / Q000235:genetics; D002452:Cell Count; D016923:Cell Death / Q000235:genetics; D003051:Cochlea / Q000294:innervation* / Q000378:metabolism / Q000473:pathology; D003638:Deafness / Q000151:congenital / Q000235:genetics* / Q000473:pathology; D004195:Disease Models, Animal; D016057:Evoked Potentials, Auditory, Brain Stem / Q000235:genetics; D006199:Hair Cells, Auditory, Inner / Q000473:pathology; D018072:Hair Cells, Auditory, Outer / Q000473:pathology; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009474:Neurons / Q000378:metabolism / Q000473:pathology*; D017084:Otoacoustic Emissions, Spontaneous / Q000235:genetics; D013136:Spiral Ganglion / Q000378:metabolism / Q000473:pathology; D014617:Vacuoles / Q000473:pathology
chemical_list: C505407:CASP3 protein, human; C505409:Casp3 protein, mouse; D053148:Caspase 3; D020169:Caspases