title: Transcriptome characterization by RNA-Seq reveals the involvement of the complement components in noise-traumatized rat cochleae.
abstract: Acoustic trauma, a leading cause of sensorineural hearing loss in adults, induces a complex degenerative process in the cochlea. Although previous investigations have identified multiple stress pathways, a comprehensive analysis of cochlear responses to acoustic injury is still lacking. In the current study, we used the next-generation RNA-sequencing (RNA-Seq) technique to sequence the whole transcriptome of the normal and noise-traumatized cochlear sensory epithelia (CSE). CSE tissues were collected from rat inner ears 1d after the rats were exposed to a 120-dB (sound pressure level) noise for 2 h. The RNA-Seq generated over 176 million sequence reads for the normal CSE and over 164 million reads for the noise-traumatized CSE. Alignment of these sequences with the rat Rn4 genome revealed the expression of over 17,000 gene transcripts in the CSE, over 2000 of which were exclusively expressed in either the normal or noise-traumatized CSE. Seventy-eight gene transcripts were differentially expressed (70 upregulated and 8 downregulated) after acoustic trauma. Many of the differentially expressed genes are related to the innate immune system. Further expression analyses using quantitative real time PCR confirmed the constitutive expression of multiple complement genes in the normal organ of Corti and the changes in the expression levels of the complement factor I (Cfi) and complement component 1, s subcomponent (C1s) after acoustic trauma. Moreover, protein expression analysis revealed strong expression of Cfi and C1s proteins in the organ of Corti. Importantly, these proteins exhibited expression changes following acoustic trauma. Collectively, the results of the current investigation suggest the involvement of the complement components in cochlear responses to acoustic trauma.
authors.affiliation: Center for Hearing and Deafness, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA. Electronic address: minalpat@buffalo.edu.
authors.forename: M
authors.initials: M
authors.lastname: Patel
authors.affiliation: Center for Computational Research, New York State Center of Excellence in Bioinformatics & Life Sciences, State University of New York at Buffalo, 701 Ellicott Street, Buffalo, NY 14260, USA; Department of Biostatistics, State University of New York at Buffalo, 701 Ellicott Street, Buffalo, NY 14260, USA; Department of Ophthalmology and Department of Medicine, State University of New York at Buffalo, 701 Ellicott Street, Buffalo, NY 14260, USA. Electronic address: zihuahu@ccr.buffalo.edu.
authors.forename: Z
authors.initials: Z
authors.lastname: Hu
authors.affiliation: Next-Generation Sequencing and Expression Analysis Core, New York State Center of Excellence in Bioinformatics and Life Sciences, State University of New York at Buffalo, 701 Ellicott Street, Buffalo, NY 14260, USA. Electronic address: jbard@buffalo.edu.
authors.forename: J
authors.initials: J
authors.lastname: Bard
authors.affiliation: Next-Generation Sequencing and Expression Analysis Core, New York State Center of Excellence in Bioinformatics and Life Sciences, State University of New York at Buffalo, 701 Ellicott Street, Buffalo, NY 14260, USA. Electronic address: jjamison@buffalo.edu.
authors.forename: J
authors.initials: J
authors.lastname: Jamison
authors.affiliation: Center for Hearing and Deafness, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA. Electronic address: qcai@buffalo.edu.
authors.forename: Q
authors.initials: Q
authors.lastname: Cai
authors.affiliation: Center for Hearing and Deafness, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA. Electronic address: bhu@buffalo.edu.
authors.forename: B H
authors.initials: BH
authors.lastname: Hu
mesh_terms: D000818:Animals; D003051:Cochlea / Q000378:metabolism*; D005260:Female; D020869:Gene Expression Profiling; D006317:Hearing Loss, Noise-Induced / Q000235:genetics*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D017423:Sequence Analysis, RNA; D015398:Signal Transduction
keywords: RNA-Seq; cochlea; complement components; noise; rat; sensory cells