Chloride channel 4 is required for nerve growth factor-induced TrkA signaling and neurite outgrowth in PC12 cells and cortical neurons

- CLC-4 siRNA inhibits the NGF-induced Cl− conductance in PC12 cells.
- CLC-4 siRNA inhibits the NGF-induced TrkA, Akt, and moesin activation.
- CLC-4 siRNA inhibits the NGF-induced neurite outgrowth in PC12 cells.
- CLC-4 siRNA inhibits the neurite outgrowth of cortical neurons.

We have previously shown that chloride ion flux plays an important role in receptor tyrosine kinase A (TrkA)-mediated signaling pathway during nerve growth factor (NGF)-induced differentiation in pheochromocytoma (PC12) cells. Here we found out that chloride channel 4 (CLC-4) is responsible for the NGF-induced neurite outgrowth in neuronal cells. Using a patch-clamp technique, we found that NGF treatment increased anionic conductance in PC12 cells, an effect which was blocked by transfection of siRNA of CLC-4. Also, the NGF-induced TrkA phosphorylation and subsequent Akt/moesin phosphorylation was suppressed in the CLC-4 knock down cells. Moreover, CLC-4 knock down also suppressed the neurite outgrowth in response to long-term treatment of NGF in PC12 cells and in primary cortical neurons. In summary, our results suggest that CLC-4 is an important mediator of the TrkA-mediated signaling pathway and thus, the NGF-induced differentiation of neuronal cells.