Proteomic Analysis of the Protein Expression in the Cochlea of Noise-Exposed Mice

ABSTRACT

BACKGROUND AND OBJECTIVES: When noise-induced hearing loss occurs, destruction of the hair cells is accompanied by mechanical injury, chemical injury, and hypoxia. Proteomics is a powerful tool for protein analysis, as it provides valuable information regarding the biochemical processes involved in diseases, monitors cellular processes, and characterizes protein expression levels. We attempted to identify the proteins associated with the pathophysiology of noise-induced hearing loss, as well as the mechanisms of this disease, using a proteomics approach. MATERIALS AND METHODS: We used BALB/C male mice. The control mice were placed in a booth without noise, while the experimental mice were exposed to noise for three hours daily for three consecutive days. Cochleae from each group were obtained for total protein extraction. The proteins were separated into numerous spots using two-dimensional electrophoresis. Seven protein spots that were strongly detected only in the noise-exposed cochleae were selected and subsequently analyzed using matrix-assisted laser desorption/ionization time of flight mass spectrometry. RESULTS: Approximately 286 protein spots were detected in the noise group. Seven selected spots were analyzed and various proteins identified, including tyrosine protein kinase MEG2, angiopoietin-like 1, heat shock 70 kDa protein, sodium dicarboxylate cotransporter 1, myeloid Elf-1-like factor, disintegrin, metalloproteinase domain 7, and activated leukocyte-cell adhesion molecule. CONCLUSIONS: We identified several proteins expressed in noise-induced hearing loss using a proteomics approach. These proteins may help us to understand the pathogenic mechanisms of noise-induced hearing loss.