SOX7 interferes with β-catenin activity to promote neuronal apoptosis.

SOX7 mediates various developmental processes. However, its role in neuronal apoptosis remains unclear. In the present study, we investigated the expression pattern and role of SOX7 in potassium deprivation-induced rat cerebellar granule neuron apoptosis. Our results showed that both mRNA and protein levels of SOX7 were upregulated when potassium was deprived. SOX7 overexpression promoted neuronal apoptosis, whereas knockdown of SOX7 protected neurons against apoptosis. Moreover, we found that β-catenin activity was suppressed during apoptosis and that β-catenin inhibition was crucial for potassium deprivation-induced neuronal apoptosis. This suppression was mediated by an interaction between SOX7 and β-catenin but not by protein degradation. Lastly, we showed that β-catenin inhibition mediated the pro-apoptotic effect of SOX7. Together, our findings demonstrated that SOX7 interfered with β-catenin activity to promote neuronal apoptosis, which acted as a novel signaling mechanism in neuronal cell death.