Dibenzazepine promotes cochlear supporting cell proliferation and hair cell regeneration in neonatal mice

Objectives To investigate the role of dibenzazepine (DBZ) in promoting supporting cell (SC) proliferation and hair cell (HC) regeneration in the inner ear. Materials and Methods Postnatal day 1 wild‐type or neomycin‐damaged mouse cochleae were cultured with DBZ. Immunohistochemistry and scanning electron microscopy were used to examine the morphology of cochlear cells, and high‐throughput RNA‐sequencing was used to measure gene expression levels. Results We found that DBZ promoted SC proliferation and HC regeneration in a dose‐dependent manner in both normal and damaged cochleae. In addition, most of the newly regenerated HCs induced by DBZ had visible and relatively mature stereocilia bundle structures. Finally, RNA sequencing detected the differentially expressed genes between DBZ treatment and controls, and interaction networks were constructed for the most highly differentially expressed genes. Conclusions Our study demonstrates that DBZ can significantly promote SC proliferation and increase the number of mitotically regenerated HCs with relatively mature stereocilia bundles in the neonatal mouse cochlea by inhibiting Notch signalling and activating Wnt signalling, suggesting the DBZ might be a new therapeutic target for stimulating HC regeneration.
Hair cell (HC) damage is the main cause of permanent hearing loss in mammals. To investigate the role of DBZ in the neonatal mouse cochlea, we cultured postnatal day 1 mouse cochleae with DBZ. We found that DBZ promoted SC proliferation and new HC generation in a dose‐dependent manner in both intact and damaged cochleae. In addition, most of the newly generated HCs induced by DBZ had visible and relatively mature stereocilia bundle structures. Our study demonstrates that DBZ can significantly promote SC proliferation and increase the number of mitotically regenerated HCs with relatively mature stereocilia bundles in the neonatal mouse cochlea by inhibiting Notch signalling and activating Wnt signalling, suggesting the DBZ might be a new therapeutic target for stimulating HC regeneration.