Reduced connexin26 in the mature cochlea increases susceptibility to noise-induced hearing lossin mice

• Authors: Xing-Xing Zhou, Huazhong University of Science and Technology; Sen Chen, Huazhong University of Science and Technology; Le Xie, Huazhong University of Science and Technology; Yu-Zi Ji, Huazhong University of Science and Technology; Xia Wu, Huazhong University of Science and Technology; Wen-Wen Wang, Huazhong University of Science and Technology; Qi Yang, Huazhong University of Science and Technology; Jin-Tao Yu, Huazhong University of Science and Technology; Yu Sun, Huazhong University of Science and Technology; Xi Lin, Emory University; Wei-Jia Kong, Huazhong University of Science and Technology
• Journal Title: International Journal of Molecular Sciences
• Volume: Volume 17, Number 3
• Publisher: MDPI | 2016-02-26
• Type of Work: Article | Final Publisher PDF
• Publisher DOI: http://doi.org/10.3390/ijms17030301
• Subjects: Health Sciences, General; Health Sciences, Medicine and Surgery
• Keywords: Connexin26; GJB2; noise-induced hearing loss

Abstract

Connexin26 (Cx26, encoded by GJB2) mutations are the most common cause of non-syndromic deafness. GJB2 is thought to be involved in noise-induced hearing loss (NIHL). However, the role of Cx26 in NIHL is still obscure. To explore the association between Cx26 and NIHL, we established a Cx26 knockdown (KD) mouse model by conditional knockdown of Cx26 at postnatal day 18 (P18), and then we observed the auditory threshold and morphologic changes in these mice with or without noise exposure. The Cx26 KD mice did not exhibit substantial hearing loss and hair cell degeneration, while the Cx26 KD mice with acoustic trauma experienced higher hearing loss than simple noise exposure siblings and nearly had no recovery. Additionally, extensive outer hair cell loss and more severe destruction of the basal organ of Corti were observed in Cx26 KD mice after noise exposure. These data indicate that reduced Cx26 expression in the mature mouse cochlea may increase susceptibility to noise-induced hearing loss and facilitate the cell degeneration in the organ of Corti.