title: Loss of the tectorial membrane protein CEACAM16 enhances spontaneous, stimulus-frequency, and transiently evoked otoacoustic emissions.
abstract: α-Tectorin (TECTA), β-tectorin (TECTB), and carcinoembryonic antigen-related cell adhesion molecule 16 (CEACAM) are secreted glycoproteins that are present in the tectorial membrane (TM), an extracellular structure overlying the hearing organ of the inner ear, the organ of Corti. Previous studies have shown that TECTA and TECTB are both required for formation of the striated-sheet matrix within which collagen fibrils of the TM are imbedded and that CEACAM16 interacts with TECTA. To learn more about the structural and functional significance of CEACAM16, we created a Ceacam16-null mutant mouse. In the absence of CEACAM16, TECTB levels are reduced, a clearly defined striated-sheet matrix does not develop, and Hensen's stripe, a prominent feature in the basal two-thirds of the TM in WT mice, is absent. CEACAM16 is also shown to interact with TECTB, indicating that it may stabilize interactions between TECTA and TECTB. Although brain-stem evoked responses and distortion product otoacoustic emissions are, for most frequencies, normal in young mice lacking CEACAM16, stimulus-frequency and transiently evoked emissions are larger. We also observed spontaneous otoacoustic emissions (SOAEs) in 70% of the homozygous mice. This incidence is remarkable considering that <3% of WT controls have SOAEs. The predominance of SOAEs >15 kHz correlates with the loss of Hensen's stripe. Results from mice lacking CEACAM16 are consistent with the idea that the organ of Corti evolved to maximize the gain of the cochlear amplifier while preventing large oscillations. Changes in TM structure appear to influence the balance between energy generation and dissipation such that the system becomes unstable.
authors: Roxelyn and Richard Pepper Department of Communication Sciences and Disorders, The Knowles Hearing Center, and m-cheatham@northwestern.edu g.p.richardson@sussex.ac.uk.
authors: Mary Ann
authors: MA
authors: Cheatham
authors: Sussex Neuroscience, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, United Kingdom, and.
authors: Richard J
authors: RJ
authors: Goodyear
authors: Department of Otolaryngology-Head and Neck Surgery, The Knowles Hearing Center, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611.
authors: Kazuaki
authors: K
authors: Homma
authors: Sussex Neuroscience, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, United Kingdom, and.
authors: P Kevin
authors: PK
authors: Legan
authors: Sussex Neuroscience, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, United Kingdom, and.
authors: Julia
authors: J
authors: Korchagina
authors: Sussex Neuroscience, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, United Kingdom, and.
authors: Souvik
authors: S
authors: Naskar
authors: Roxelyn and Richard Pepper Department of Communication Sciences and Disorders, The Knowles Hearing Center, and.
authors: Jonathan H
authors: JH
authors: Siegel
authors: Roxelyn and Richard Pepper Department of Communication Sciences and Disorders, The Knowles Hearing Center, and Department of Neurobiology, Northwestern University, Evanston, Illinois 60208.
authors: Peter
authors: http://orcid.org/0000-0002-9731-6591
authors: P
authors: Dallos
authors: Department of Otolaryngology-Head and Neck Surgery, The Knowles Hearing Center, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611.
authors: Jing
authors: J
authors: Zheng
authors: Sussex Neuroscience, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, United Kingdom, and m-cheatham@northwestern.edu g.p.richardson@sussex.ac.uk.
authors: Guy P
authors: GP
authors: Richardson
mesh_terms: D000161:Acoustic Stimulation; D000818:Animals; D015815:Cell Adhesion Molecules / Q000172:deficiency* / Q000235:genetics; D016057:Evoked Potentials, Auditory, Brain Stem / Q000235:genetics; D016326:Extracellular Matrix Proteins / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000235:genetics; D057809:HEK293 Cells; D006801:Humans; D047468:Immunoprecipitation; D008564:Membrane Potentials / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D046529:Microscopy, Electron, Transmission; D009925:Organ of Corti / Q000166:cytology*; D017084:Otoacoustic Emissions, Spontaneous / Q000235:genetics / Q000502:physiology*; D018408:Patch-Clamp Techniques; D013680:Tectorial Membrane / Q000502:physiology* / Q000648:ultrastructure; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: C575021:CEACAM16 protein, mouse; D015815:Cell Adhesion Molecules; D016326:Extracellular Matrix Proteins; D001616:beta-Galactosidase
keywords: CEACAM16; Hensen's stripe; cochlea; mouse; otoacoustic emissions; tectorial membrane