Profiles of oxidative stress-related microRNA and mRNA expression in auditory cells.

Oxidative stress and high levels of reactive oxygen species (ROS) are risk factors of auditory cell injury and hearing impairment. MicroRNAs (miRNAs) are critical for the post-transcriptional regulation of gene expression and cell proliferation and survival. However, little is known about the impact of oxidative stress on the expression of miRNAs and their targeted mRNAs in auditory cells. We employed a cell model of oxidative stress by treatment of House Ear Institute-Organ of Corti 1 (HEI-OC1) cells with different concentrations of tert-butyl hydroperoxide (t-BHP) to examine the t-BHP-induced production of ROS and to determine the impact of t-BHP treatment on the relative levels of miRNA and mRNA transcripts in HEI-OC1 cells. We found that treatment with different concentrations of t-BHP promoted the production of ROS, but inhibited the proliferation of HEI-OC1 cells in a dose- and time-dependent manner. Furthermore, treatment with t-BHP induced HEI-OC1 cell apoptosis. Further microarray analyses revealed that treatment with t-BHP increased the transcription of 35 miRNAs, but decreased the expression of 40 miRNAs. In addition, treatment with t-BHP up-regulated the transcription of 2076 mRNAs, but down-regulated the levels of 580 mRNA transcripts. Notably, the up-regulated (or down-regulated) miRNAs were associated with the decreased (or increased) expression of predicted targeted mRNAs. Importantly, these differentially expressed mRNAs belonged to different functional categories, forming a network participating in the oxidative stress-related process in HEI-OC1 cells. Therefore, our findings may provide new insights into understanding the regulation of miRNAs on the oxidative stress-related gene expression and function in auditory cells. Copyright 2010 Elsevier B.V. All rights reserved.