Chemical Chaperone 4-Phenylbutyrate Prevents Hearing Loss And Cochlear Hair Cell Death In Cdh23(Erl/Erl) Mutant Mice

We previously developed Cdh23(erl/erl) mutant mice (erl mice) as a model of hearing loss for otoprotective drug evaluation and showed that the erl mutation leads to hearing loss related to endoplasmic reticulum (ER) stress-induced cochlear hair cell apoptosis. Small molecular chemical chaperones, 4-phenylbutyrate (4PBA), targeting ER stress exert a neuroprotective effect. To evaluate whether 4PBA exerts an otoprotective effect, we intraperitoneally injected erl mice with 4PBA daily from postnatal age day 7 up to 12 weeks. Our results showed that treatment with 4PBA significantly alleviated hearing loss and suppressed hair cell death in erl mice. In addition, ER stress-related proteins were downregulated by 4PBA treatment. Our study showed that 4PBA exerts an otoprotective effect, which provides the potential to repurpose the drug for otoprotection. Copyright (c) 2018 Wolters Kluwer Health, Inc. All rights reserved.