Abstract
Conclusion: The present study suggests that adeno-associated viral vector AAV2-mediated expression of activity-dependent neurotrophic factor-9 (ADNF-9) in the cochlea could be a promising approach to protect the cochlea from aminoglycoside-induced impairment, although a further in vivo study is needed. Objectives: To construct vectors over-expressing ADNF-9 to overcome its short half-life and investigate the effect of ADNF-9 on aminoglycoside-induced hair cell impairment. Methods: We ligated ADNF-9 cDNA to the signal and leader peptides of neurotrophin 4 (NT4) and the fusion gene was named NT4-ADNF-9. NT4-ADNF-9 was subcloned into the prokaryotic expression vector pBV220 to obtain pBV220/NT4-ADNF-9. The induced recombinant ADNF-9 proteins were added into the dorsal root ganglia (DRG) cultures of embryonic day 8 chickens. In addition, we constructed the recombinant vector rAAV-NT4-ADNF-9 and transfected rat neonatal organ of Corti explants in the presence of aminoglycoside G418. Results: Our data showed that the induced expression of ADNF-9 protein could promote cultured DRG neuronal survival and neurite outgrowth. In addition, transfection of rAAV-NT4-ADNF-9 could prevent hair cell loss induced by G418 treatment in the rat organ of Corti.
Acknowledgement
The work was supported by the foundation Tysta Skolan, Karolinska Institutet and National natural science grant of China (30471877).
Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.