Gene expression profile of the germaniumu dioxide-related hearing loss cochlea in CBA mice

Various organ failure induced by chronic intake of GeO2 is one of the well known disease related to mitochondrial dysfunction. The 0.15% GeO2 treated CBA mice shows severe hearing loss in 4M. Here we analyzed cochlear gene expression of 6 months old CBA mice using microarrays treated with normal chow or that containing 0.15% GeO2 for four months. Auditory brainstem response (ABR) analysis confirmed that severe age-related hearing loss occured in GeO2 treated mice, whereas no hearing loss occured in normal chow treated mice. Comprehensive gene expression analysis identified genes correlated with GeO2-induced mithochodrial dysfunction genes and revealed that 28 genes encoding components of the mitochondrial respiratory chain were significantly down-regulated. These observations provide evidence that GeO2-induced hearing loss is associated with the down-regulation of genes involved in the mitochondrial respiratory chain complexes in the cochlea of CBA mice.

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