Cell Specific Transcriptional Responses to Heat Shock in the Mouse Utricle Epithelium

To determine the transcriptional responses to heat shock of inner ear sensory hair cells and supporting cells, we performed cell-type-specific transcriptional profiling using the RiboTag method, which allows for immunoprecipitation of actively translating mRNAs from specific cell types. RNA-Seq differential gene expression analyses demonstrated that RiboTag identified known cell type-specific markers as well as new markers for hair cells and supporting cells. Gene expression differences suggest that both hair cells and supporting cells exhibit a transcriptional heat shock response. However, hair cells and supporting cells expressed different members of the heat shock protein family in response to heat stress, and supporting cells expressed a larger number of HSPs. Only one HSP, Chaperonin Containing T-Complex Polypeptide 1 Subunit 8, (CCT8) was uniquely induced in hair cells. Together our data indicate that hair cells exhibit a limited but unique heat shock response, and supporting cells exhibit a broader and more robust transcriptional response to protective heat stress. Overall design: RNA-seq comparisons of control (CON) versus Heat-shock treated cultured utricles. The RNA was isolated fom ribotag-enriched immunoprecipates (IP) and compared to RNA isolated from input to identify genes enriched in the IP. Two cre-expressing mouse lines were used to obtain either hair-cell enriched IP samples (Gfi1-Cre) or supporting cell enrich IP samples (GLAST-CreER).