Neuroglobin is an endogenous neuroprotective protein， but the underlying neuroprotective mechanisms remain to be elucidated. Our previous yeast two-hybrid screening study identified that Dishevelled-1， a key hub protein of Wnt/β-Catenin signaling， is an interaction partner of Neuroglobin. In this study， we further examined the role of Neuroglobin in regulating Dishevelled-1 and the downstream Wnt/β-Catenin and NFκB signaling pathway. We found that Neuroglobin directly interacts with Dishevelled-1 by co-immunoprecipitation， and the two proteins are co-localized in both cytoplasma and nucleus of SK-N-SH cells. Moreover， the ectopic expression of Neuroglobin promotes the degradation of exogenous and... More
Neuroglobin is an endogenous neuroprotective protein， but the underlying neuroprotective mechanisms remain to be elucidated. Our previous yeast two-hybrid screening study identified that Dishevelled-1， a key hub protein of Wnt/β-Catenin signaling， is an interaction partner of Neuroglobin. In this study， we further examined the role of Neuroglobin in regulating Dishevelled-1 and the downstream Wnt/β-Catenin and NFκB signaling pathway. We found that Neuroglobin directly interacts with Dishevelled-1 by co-immunoprecipitation， and the two proteins are co-localized in both cytoplasma and nucleus of SK-N-SH cells. Moreover， the ectopic expression of Neuroglobin promotes the degradation of exogenous and endogenous Dishevelled-1 through the proteasomal degradation pathway. Furthermore， our results showed that Neuroglobin significantly inhibits the luciferase activity of Topflash reporter and the expression of β-Catenin mediated by Dishevelled-1 in SK-N-SH cells. In addition， we also documented that Neuroglobin enhances TNF-α-induced NFκB activation via down-regulating Dishevelled-1. Finally， 3-(4，5-Dimethylthiazol-2-Yl)-2，5-Diphenyltetrazolium Bromide (MTT) assays showed that Neuroglobin is an important neuroprotectant that protects SK-N-SH cells from TNF-α-induced decrease in cell viability. Taken together， these findings demonstrated that Neuroglobin functions as an important modulator of the Wnt/β-Catenin and NFκB signaling pathway through regulating Dishevelled-1.
