Expression and Distribution of Tumor Necrosis Factor-Alpha in Mice Cochlea Exposed to Noise / 대한이비인후과학회지

ABSTRACT

BACKGROUND AND OBJECTIVES: Recent studies have shown that inflammatory responses occur in the inner ear under various damaging conditions including noise-overstimulation.Identification of time-dependent expression patterns of pro-inflammatory cytokines during the response initiation should lead to rational therapeutic strategies that block the response and reduce the damaging sequelae. MATERIALS AND METHOD: We evaluated the time-dependent expression pattern of pro-inflammatory cytokines in noise-exposed mouse cochlea (white noise, 120 dB SPL, 3 hours) using immunohistochemistry and reverse transcriptase-polymerase chain reaction(RT-PCR). RESULTS: The most potent pro-inflammatory cytokine, the tumor necrosis factor-alpha (TNF-alpha), was up-regulated after noise exposure. Immunohistochemical analyses showed that the TNF-alpha expression was distinctively induced within the spiral ganglion and stria vascularis. RT-PCR showed that TNF-alpha was induced shortly after noise exposure and persisted upto seven days following noise exposure. CONCLUSION: Taken together, acoustic trauma induces cochlear inflammation and the data suggest that TNF-alpha may have some role in cochlea damage that occur following noise exposure.