JNK activation and up-regulation of thioredoxin reductase (TrxR) in the rat cochlea following styrene exposure

Details

• Personal Author:
  Chen GD ; Henderson D ; Li M
• Description:
  Styrene, a widely used industrial chemical, is ototoxic. It causes death of auditory hair cells after about 7 days of exposure (800 mg/kg/day) through apoptosis (Chen et al., 2007). This study was designed to determine styreneinduced alterations in the cochlea underlying the apoptotic cell death. Thioredoxin(Trx)/thioredoxin reductase(TrxR) system plays an important role in maintaining cellular redox balance and inhibiting JNK pathway, which leads to apoptotic cell death. Long Evans rats were exposed to styrene by gavage at a dose of 800 mg/kg in oil for 4 days or as controls by oil gavage alone. Cochlear tissues were sampled 1 hour after the last exposure. TrxR and p-JNK were determined by Western blot analysis. The results showed a remarkable increase of p-JNK in the styrene exposed group compared to the oil control group. However, TrxR level in the styrene exposed level was also up-regulated. The data indicated that styrene did not cause damage to the Trx/TrxR redox system. We speculate that styrene exposure results in over-production of reactive oxygen species (ROS), which activates stress signaling pathways leading to apoptotic cell death. The over-produced ROS can also oxidize Trx and the overloaded oxidized Trx may stimulate synthesis of TrxR. This study was supported by NIOSH grant 1R01OH008113-01A1. [Description provided by NIOSH]
• Subjects:
  Age Factors Animals Hearing Hearing Loss Hearing Loss, Noise-Induced Laboratories Noise Occupational Health Safety Styrene
• Keywords:
  Age-factors Cell-damage Exposure-levels Hearing-disorders Hearing-loss Laboratory-animals Molecular-structure Noise-exposure Noise-induced-hearing-loss Ototoxicity Styrenes

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• ISSN:
  0742-3152
• Publisher:
  Association for Research in Otolaryngology
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Abstract or Summary
• Place as Subject:
  Maryland ; Missouri ; New York ; OSHA Region 2 ; OSHA Region 3 ; OSHA Region 7
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  32
• NIOSHTIC Number:
  nn:20041700
• Citation:
  Abstr Midwinter Res Meet Assoc Res Otolaryngol 2009 Feb; 32:202
• Editor(s):
  Santi PA
• Federal Fiscal Year:
  2009
• NORA Priority Area:
  Manufacturing ; Wholesale and Retail Trade
• Performing Organization:
  Washington University, St. Louis
• Peer Reviewed:
  False
• Start Date:
  20000401
• Source Full Name:
  Abstracts of the 32nd Midwinter Research Meeting of the Association for Research in Otolaryngology, Febuary 14-19, 2009, Baltimore, Maryland
• End Date:
  20130914
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:ebef99dd2a9b37dc61290553303223bd759699077bb738885b4ff792553089ec1bbaf6d01a80d2d87b83fddaf0040b28123a64c27170ee5ccc384bbde4b3e750
• Download URL:
  https://stacks.cdc.gov/view/cdc/194191/cdc_194191_DS1.pdf
• File Type:
  [PDF - 95.18 KB ]