Differential gene expression in the rat cochlea after exposure to impulse noise.
Understanding the molecular biology of noise trauma is vital to developing effective and timely interventions. In a model of explosion-mediated impulse noise injury, differential gene expression was studied in whole rat cochlea preparations at 3 and 24 h following the exposure. We developed a technique using mRNA from a single cochlea on each oligonucleotide microarray to avoid pooling of mRNA samples. Application of a conservative statistical analysis approach resulted in the identification of 61 differentially expressed genes. Within 3 h after the exposure, there was an up-regulation of immediate early genes, mainly transcription factors and genes involved in the tissue's response to oxidative stress. No genes were found to be significantly down-regulated. At 24 h following the exposure, up-regulated genes included members of inflammatory and antioxidant pathways and one gene involved in glutathione metabolism was down-regulated. A subset of genes was confirmed by real-time reverse transcriptase-polymerase chain reaction (RT-PCR). The present study demonstrates the power of the microarray technique in providing a global view of the gene regulation following noise exposure, and in identifying genes that may be mechanistically important in hearing loss, and thereby serve as a basis for the development of therapeutic interventions.
Kirkegaard
M
M
Center for Hearing and Communication Research, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden. mette.kirkegaard@ki.se
Murai
N
N
Risling
M
M
Suneson
A
A
Järlebark
L
L
Ulfendahl
M
M
D000161:Acoustic Stimulation / Q000379:methods; D000818:Animals; D003051:Cochlea / Q000378:metabolism* / Q000528:radiation effects; D005260:Female; D015870:Gene Expression / Q000502:physiology* / Q000528:radiation effects; D020869:Gene Expression Profiling / Q000379:methods; D005786:Gene Expression Regulation / Q000502:physiology* / Q000528:radiation effects; D009622:Noise; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods
D012333:RNA, Messenger