Cochlin Deficiency Protects Against Noise-Induced Hearing Loss

Research output: Contribution to journalArticlepeer-review

  • External authors:
  • Richard Seist
  • Lukas Landegger
  • Nahid G. Robertson
  • Sasa Vasilijic
  • Konstantina M Stankovic

Abstract

Cochlin is the most abundant protein in the inner ear. To study its function in response to noise trauma, we exposed adolescent wild-type (Coch+/+) and cochlin knock-out (Coch-/-) mice to noise (8-16 kHz, 103 dB SPL, 2h) that causes a permanent threshold shift and hair cell loss. Two weeks after noise exposure, Coch-/- mice had substantially less elevation in noise-induced auditory thresholds and hair cell loss than Coch+/+ mice, consistent with cochlin deficiency providing protection from noise trauma. Comparison of pre-noise exposure thresholds of auditory brain stem responses (ABRs) and distortion product otoacoustic emissions (DPOAEs) in Coch-/- mice and Coch+/+ littermates revealed a small and significant elevation in thresholds of Coch-/- mice, overall consistent with a small conductive hearing loss in Coch-/- mice. We show quantitatively that the pro-inflammatory component of cochlin, LCCL, is upregulated after noise exposure in perilymph of wild-type mice compared to unexposed mice, as is the enzyme catalyzing LCCL release, aggrecanase1, encoded by Adamts4. We further show that upregulation of pro-inflammatory cytokines in perilymph and cochlear soft-tissue after noise exposure is lower in cochlin knock-out than wild-type mice. Taken together, our data demonstrate for the first time that cochlin deficiency results in conductive hearing loss that protects against physiologic and molecular effects of noise trauma.

Bibliographical metadata

Original languageEnglish
JournalFrontiers in Molecular Neuroscience
Publication statusAccepted/In press - 16 Apr 2021

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