Sensory epithelial cells in the organ of Corti survive throughout life. However, factors for sensory epithelial cell survival are poorly understood at the present time. Here we demonstrated that brain-derived neurotrophic factor (BDNF), a factor committing to neuronal survival, promotes the survival of sensory epithelial cells (OC1) through phosphatidylinositide 3'-OH kinase (PI3K)/protein kinase B (Akt) and/or nuclear factor kappa B (NF-κB)/B cell lymphoma 2 (Bcl-2) pathways. BDNF activated PI3K/Akt kinases and increased NF-κB/Bcl-2 activity or expression in association with the survival of OC1 cells in vitro. LY294002, a specific inhibitor for PI3K, and pyrrolidine dithiocarbamate (PDTC), an inhibitor for NF-κB, abrogated the protective effect of BDNF on OC1 cells, causing the increased expression of caspase 3 and the apoptotic cell numbers in vitro. Similarly, a dominant negative mutant of I kappa B alpha (IκBαM, a specific inhibitor of NF-κB) abrogated the protective effect of BDNF on OC1 cells. The data demonstrate that BDNF promotes the survival of sensory epithelial cells through the PI3K/Akt and NF-κB/Bcl-2 signaling pathways.
- Cell survival
- Sensory epithelial cells