Abstract:

Objective   To investigate the possible involvement of AIF and PARP-1 in gentamicin-induced vestibular hair cell death. Methods   Vestibular organ obtained from postnatal day (p) p3 or p4 rats were maintained in tissue culture medium and were exposed to 2 mg/mL gentamicin (GM) for up to 72 h. Apoptosis was determined by flow cytometry (FCW). Expressions of AIF and PARP-1 mRNA were determined by RT-PCR. Expressions of the mitochondrial protein and cytoplasm protein of AIF were detected by Western blotting. The expression of PARP-1 protein was detected by Western blotting. Results   GM induced apoptosis in vestibular hair cells. The number of apoptotic cells increased as shown by FCW. RT-PCR showed an up-regulation of AIF and PARP-1 mRNA in the GM group. Western blotting results showed that mitochondrial protein of AIF was decreased after gentamicin exposure while cytoplasm protein of AIF was increased. Expression of protein of PARP-1 was increased after gentamicin exposure. Conclusion   AIF participates in gentamicin-induced apoptosis of vestibular hair cells. PARP-1 might participate in the action of AIF pathway.

Key words: Apoptosisinducing factor； Vestibular sensory cell； Apoptosis