Disturbance in the protein landscape of cochlear perilymph in an Alzheimer’s disease mouse model

by Masatoshi Fukuda, Hiroki Okanishi, Daisuke Ino, Kazuya Ono, Satoru Kawamura, Eri Wakai, Tsuyoshi Miyoshi, Takashi Sato, Yumi Ohta, Takashi Saito, Takaomi C. Saido, Hidenori Inohara, Yoshikatsu Kanai, Hiroshi Hibino

Hearing loss is a pivotal risk factor for dementia. It has recently emerged that a disruption in the intercommunication between the cochlea and brain is a key process in the initiation and progression of this disease. However, whether the cochlear properties can be influenced by pathological signals associated with dementia remains unclear. In this study, using a mouse model of Alzheimer’s disease (AD), we investigated the impacts of the AD-like amyloid β (Aβ) pathology in the brain on the cochlea. Despite little detectable change in the age-related shift of the hearing threshold, we observed quantitative and qualitative alterations in the protein profile in perilymph, an extracellular fluid that fills the path of sound waves in the cochlea. Our findings highlight the potential contribution of Aβ pathology in the brain to the disturbance of cochlear homeostasis.