Molecular study of age-related hearing disorders using Drosophila. Leo Tsuda, Yasuhiro Omata, Yasutoyo Yamasaki, Young-Mi Lim. Animal Models of Aging, National Center for Geriatrics and Grontology, Aich, Japan.

   Cell survival of sensory neurons is essential for the long-term maintenance of sensory functions. Its defect leads to the onset of age-related sensory defects suffered by a great number of aged human populations, such as hearing loss and retinitis pigmentosa. Noise induced hearing loss (NIHL) is thought to be a model system for studying the pathological nature of age-related hearing disorders. Research toward the molecular mechanism of NIHL, however, has been hampered due to the lack of efficient assay systems in model organisms. In this work, we tried to establish a model system to analyze the formation of NIHL using fruit fly and mouse. In the previous study, we have revealed that Ebi, a fly homologue of TBL1, which is involved in age-related hearing disorder in humans, forms a complex with AP-1 and represses expression of the pro-apoptotic genes in photoreceptor cells. In this time we monitored the survival of auditory sensory neurons by physiological methods, and found that Ebi and TBL1 is required for protecting sensory cells from toxic effect induced by sound stimulation. Thus studying ebi and TBL1 in the sensory cells survival might lead to reveal the molecular mechanism of NIHL and age-related hearing disorders.