The protective role of Wnt3a in peroxynitrite-induced damage of cochlear hair cells in vitro.

OBJECTIVE

To investigate the effect of peroxynitrite on the cultured cochlear hair cells of C57BL/6 P3 mice in vitro as well as the role of Wnt3a, as an activator of the canonical Wnt signaling pathway, underlying the action of such an oxidative stress.

METHODS

The in vitro primary cultured cochlear hair cells were subjected to l00 μM peroxynitrite and l00 μM peroxynitrite +25 ng/mL Wnt3a for 24 h, the cell survival and morphological changes were examined by immunofluorescence and transmission electron microscopy.

RESULTS

The number of surviving hair cells was significantly reduced in the 100 μM peroxynitrite group, while it was significantly higher in the Wnt3a + peroxynitrite treated group compared with the peroxynitrite treated group. The transmission electron microscopy showed that exposure to peroxynitrite induced a dramatic decrease in the number of mitochondria and severely disrupted mitochondrial ultrastructure, while Wnt3a clearly diminished the disruption of mitochondrial structure and preserved a higher number of mitochondria.

CONCLUSION

These results indicated that peroxynitrite could cause oxidative damage to the cochlear hair cells, and low concentrations of Wnt3a has a protective effect against oxidative damage.

LEVEL OF EVIDENCE

Level 2.