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다국어 초록 (Multilingual Abstract)

Background and Objectives: When noise-induced hearing loss occurs, destruction of the hair cells is accompanied by mechanical injury, chemical injury, and hypoxia. Proteomics is a powerful tool for protein analysis, as it provides valuable information regarding the biochemical processes involved in diseases, monitors cellular processes, and characterizes protein expression levels. We attempted to identify the proteins associated with the pathophysiology of noise-induced hearing loss, as well as the mechanisms of this disease, using a proteomics approach.

Materials and Methods: We used BALB/C male mice. The control mice were placed in a booth without noise, while the experimental mice were exposed to noise for three hours daily for three consecutive days. Cochleae from each group were obtained for total protein extraction. The proteins were separated into numerous spots using two-dimensional electrophoresis. Seven protein spots that were strongly detected only in the noise-exposed cochleae were selected and subsequently analyzed using matrix-assisted laser desorption/ionization time of flight mass spectrometry.

Results: Approximately 286 protein spots were detected in the noise group. Seven selected spots were analyzed and various proteins identified, including tyrosine protein kinase MEG2, angiopoietin-like 1, heat shock 70 kDa protein, sodium dicarboxylate cotransporter 1, myeloid Elf-1-like factor, disintegrin, metalloproteinase domain 7, and activated leukocyte-cell adhesion molecule.

Conclusions: We identified several proteins expressed in noise-induced hearing loss using a proteomics approach. These proteins may help us to understand the pathogenic mechanisms of noise-induced hearing loss.

다국어 초록 (Multilingual Abstract)

Introduction

Noise is a common cause of sensorineural hearing impairment in industrialized countries. Millions of people currently have disabilities caused by noise-induced hearing loss and experience problems in communication with families, colleagues, and friends.1) In particular, tinnitus is one of the symptoms of noise-induced hearing loss that brings severe social isolation and leads to degraded quality of life. Noise exposure can physically destroy the tympanic membrane, middle ear, and inner ear and can alter the intracellular pathways that lead to cell necrosis or apoptosis, and induced hearing loss worsens. In addition, noise stimulation was recently found to induce metabolic changes inside the inner ear. Possible mechanisms underlying this noise-induced tissue damage are oxidative stress and the reduction of cochlear blood flow.2) Studies have been conducted in the last few decades on mechanical trauma and the metabolic damage of mechanical changes. Vascular endothelial growth factor, nuclear factor κB, glucose transporter-1, and hypoxia-inducible factor-1α are thought to be causes of noise-induced hearing loss. Most of them were histologically confirmed by immunohistochemical and fluorescence staining.4,5,6)Proteomics is a powerful tool for protein analysis, as it provides valuable information regarding the biochemical processes involved in diseases, monitors cellular processes, and characterizes protein expression levels. We can understand the pathophysiology of disease through analysis of the proteins involved using proteomics technology, which includes two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS). These techniques can be used to produce a high-resolution two-dimensional map, in which individual (stained) proteins appear as spots of various sizes and intensities that depend on the amount of each protein in the sample.7,8)To understand the proteins associated with the pathophysiology of noise-induced hearing loss, as well as the mechanisms of the disease, we compared expressed proteins in noise-exposed mice with those in unexposed mice using this proteomics approach. For this, we investigated expressed protein spots only in noise-exposed mice.

Materials and Methods

Materials As experimental groups, 8-week-old BALB/c mice with normal Preyer's reflexes and normal hearing thresholds in auditory brainstem response were studied.

Methods

Experimental setting All mice were placed in separate soundproof booths with blocks to outside noise. We set an amplifier (R-399, INTER M, Seoul, Korea) in the left side of the room and placed an 8 Ω resistance speaker (290-8L, ALTEC LANSING, Oklahoma City, OK, USA) on the amplifier with a 45 degree horn.

Anesthesia of experimental groups All mice were anesthetized (Ketamine hydrochloride 59 mg/kg and xylazine 1.3 mg/kg body weight) via intraperitoneal injection. If necessary, we injected an additional half dose of anesthestics.

Threshold measurement The auditory brainstem response (ABR) to click stimuli was recorded, and thresholds were obtained for each ear. Hearing thresholds are measured at wave I lowering by 10 dB from an intensity of 90 dB hearing level (HL). When the wave was not definite, we checked threshold lowering by 5 dB. Click stimuli were filtered from 100 to 3,000 Hz, and the frequency was 1,024/min.

Noise exposure procedure Ten mice were exposed continuously for 3 h/day to a 120 dB sound pressure level (SPL) broad band click sound for 1-5 consecutive days. In the noise booth, mice were randomly divided into two groups, and their location inside the booth was changed daily so that each animal was exposed to the same level of noise. Ten normal BALB/c mice kept for 3 h/day for 5 consecutive days in the same noise booth without noise were used as the control group. Acoustic trauma was induced by a continuous pure tone of 6 kHz generate...

참고문헌 (Reference)

1 김창훈, "프로테오믹스" 대한이비인후과학회 47 (47): 705-713, 2004

2 Ohlemiller KK, "Vulnerability to noise-induced hearing loss in ‘middle-aged’ and young adult mice: a dose-response approach in CBA, C57BL, and BALB inbred strains" 149 : 239-247, 2000

3 Picciotti PM, "Vascular endothelial growth factor (VEGF) expression in noise-induced hearing loss" 214 : 76-83, 2006

4 Chung JW, "Up-regulation of hypoxia-inducible factor-1 alpha by cobalt chloride prevents hearing loss in noise-exposed mice" 31 : 153-159, 2011

5 Lindquist S, "The heat-shock response" 55 : 1151-1191, 1986

6 Knepper MA, "Proteomics and the kidney" 13 : 1398-1408, 2002

7 Ahram M, "Proteomic analysis of human prostate cancer" 33 : 9-15, 2002

8 Park KS, "Proteomic analysis and molecular characterization of tissue ferritin light chain in hepatocellular carcinoma" 35 : 1459-1466, 2002

9 Beranova-Giorgianni S, "Preliminary analysis of the mouse cerebellum proteome" 98 : 135-140, 2002

10 Lang H, "Nuclear factor kappaB deficiency is associated with auditory nerve degeneration and increased noise-induced hearing loss" 26 : 3541-3550, 2006