- Arun P, Wang Y, Wei Y, Oguntayo S, Biggemann L, Nambiar MP. (2011) Repeated Blast Exposures Lead to Changes in Hearing Related Gene Expression in Mice Brain. NATO Research & Technology Organisation Scientific Publications RTO-MP-HFM-207, 1-10.
Accumulating clinical and animal studies suggest that primary blast exposure causes traumatic brain injury (TBI) and subsequent neuropsychiatric impairments. Activation of multiple biochemical pathways in the brain seems to be the basis for the observed neuropathology and neuropsychiatric impairments after blast exposure. To advance the studies on the biochemical mechanism of blast induced TBI, we have developed a mouse model of repeated blast exposures. Adult C57BL/6J mice were exposed to repeated (3 exposures in 2 to 30 min) blast overpressure exposure (20.56 psi) in a shock tube. The mice were euthanized 6 h after blast exposure and differential protein expression in the brain samples were determined by proteomic analysis. Our data showed that calretinin and parvalbumin, two of the major proteins involved in auditory dysfunction and tinnitus were up-regulated as early as 6 h post-blast exposures. The changes in the level of expression of those proteins were further confirmed by Western blot analyses. These results suggest that repeated blast exposures results in alteration in the brain levels of multiple proteins reportedly associated with hearing impairment and tinnitus. Additionally, microarray analysis indicated that microRNA-181a that plays a key role in hair cell regeneration and auditory function was decreased in the brain after repeated blast exposures. Since hearing impairment and tinnitus are prevalent dysfunctions after blast exposures, the data provides a molecular basis of changes in auditory system leading to hearing impairment and tinnitus after blast exposure.