{"title":"Activation of the NRF2 pathway in Keap1-knockdown mice attenuates progression of age-related hearing loss.","authors":"Tetsuya Oishi, Daisuke Matsumaru, Nao Ota, Hiroshi Kitamura, Tianxiang Zhang, Yohei Honkura, Yukio Katori, Hozumi Motohashi","doi":"10.1038/s41514-020-00053-4","DOIUrl":null,"url":null,"abstract":"<p><p>Age-related hearing loss (AHL) is a progressive sensorineural hearing loss in elderly people. Although no prevention or treatments have been established for AHL, recent studies have demonstrated that oxidative stress is closely related to pathogenesis of AHL, suggesting that suppression of oxidative stress leads to inhibition of AHL progression. NRF2 is a master transcription factor that regulates various antioxidant proteins and cytoprotection factors. To examine whether NRF2 pathway activation prevents AHL, we used Keap1-knockdown (Keap1<sup>FA/FA</sup>) mice, in which KEAP1, a negative regulator of NRF2, is decreased, resulting in the elevation of NRF2 activity. We compared 12-month-old Keap1<sup>FA/FA</sup> mice with age-matched wild-type (WT) mice in the same breeding colony. In the Keap1<sup>FA/FA</sup> mice, the expression levels of multiple NRF2 target genes were verified to be significantly higher than the expression levels of these genes in the WT mice. Histological analysis showed that cochlear degeneration at the apical and middle turns was ameliorated in the Keap1<sup>FA/FA</sup> mice. Auditory brainstem response (ABR) thresholds in the Keap1<sup>FA/FA</sup> mice were significantly lower than those in the WT mice, in particular at low-mid frequencies. Immunohistochemical detection of oxidative stress markers suggested that oxidative stress accumulation was attenuated in the Keap1<sup>FA/FA</sup> cochlea. Thus, we concluded that NRF2 pathway activation protects the cochlea from oxidative damage during aging, in particular at the apical and middle turns. KEAP1-inhibiting drugs and phytochemicals are expected to be effective in the prevention of AHL.</p>","PeriodicalId":19334,"journal":{"name":"NPJ Aging and Mechanisms of Disease","volume":null,"pages":null},"PeriodicalIF":5.4000,"publicationDate":"2020-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1038/s41514-020-00053-4","citationCount":"15","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"NPJ Aging and Mechanisms of Disease","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1038/s41514-020-00053-4","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GERIATRICS & GERONTOLOGY","Score":null,"Total":0}
引用次数: 15
Abstract
Age-related hearing loss (AHL) is a progressive sensorineural hearing loss in elderly people. Although no prevention or treatments have been established for AHL, recent studies have demonstrated that oxidative stress is closely related to pathogenesis of AHL, suggesting that suppression of oxidative stress leads to inhibition of AHL progression. NRF2 is a master transcription factor that regulates various antioxidant proteins and cytoprotection factors. To examine whether NRF2 pathway activation prevents AHL, we used Keap1-knockdown (Keap1FA/FA) mice, in which KEAP1, a negative regulator of NRF2, is decreased, resulting in the elevation of NRF2 activity. We compared 12-month-old Keap1FA/FA mice with age-matched wild-type (WT) mice in the same breeding colony. In the Keap1FA/FA mice, the expression levels of multiple NRF2 target genes were verified to be significantly higher than the expression levels of these genes in the WT mice. Histological analysis showed that cochlear degeneration at the apical and middle turns was ameliorated in the Keap1FA/FA mice. Auditory brainstem response (ABR) thresholds in the Keap1FA/FA mice were significantly lower than those in the WT mice, in particular at low-mid frequencies. Immunohistochemical detection of oxidative stress markers suggested that oxidative stress accumulation was attenuated in the Keap1FA/FA cochlea. Thus, we concluded that NRF2 pathway activation protects the cochlea from oxidative damage during aging, in particular at the apical and middle turns. KEAP1-inhibiting drugs and phytochemicals are expected to be effective in the prevention of AHL.
期刊介绍:
npj Aging and Mechanisms of Disease is an online open access journal that provides a forum for the world’s most important research in the fields of aging and aging-related disease. The journal publishes papers from all relevant disciplines, encouraging those that shed light on the mechanisms behind aging and the associated diseases. The journal’s scope includes, but is not restricted to, the following areas (not listed in order of preference): • cellular and molecular mechanisms of aging and aging-related diseases • interventions to affect the process of aging and longevity • homeostatic regulation and aging • age-associated complications • translational research into prevention and treatment of aging-related diseases • mechanistic bases for epidemiological aspects of aging-related disease.