Pevonedistat - CAS 905579-51-3

It has been reported that MLN4924 can inhibit cell growth and metastasis in various kinds of cancer. We have reported that MLN4924 is able to inhibit angiogenesis through the induction of cell apoptosis both in vitro and in vivo models. Moreover, Neddylation inhibition using MLN4924 triggered the accumulation of pro-apoptotic protein NOXA in Human umbilical vein endothelial cells (HUVECs). However, the mechanism of MLN4924-induced NOXA up-regulation has not been addressed in HUVECs yet. In this study, we investigated how MLN4924 induced NOXA expression and cellular apoptosis in HUVECs treated with MLN4924 at indicated concentrations. MLN4924-induced apoptosis was evaluated by Annexin V-FITC/PI analysis and expression of genes associated with apoptosis was assessed by Quantitative RT-PCR and western blotting. As a result, MLN4924 triggered NOXA-dependent apoptosis in a dose-dependent manner in HUVECs. Mechanistically, inactivation of Neddylation pathway caused up-regulation of activating transcription factor 4 (ATF-4), a substrate of Cullin-Ring E3 ubiquitin ligases (CRL). NOXA was subsequently transactivated by ATF-4 and further induced apoptosis. More importantly, knockdown of ATF-4 by siRNA significantly decreased NOXA expression and apoptotic induction in HUVECs.

Redundancies in both the ubiquitin and epithelial sodium transport pathways allude to their importance of proteolytic degradation and ion transport in maintaining normal cell function. The classical pathway implicated in ubiquitination of the epithelial sodium channel (ENaC) involves Nedd4-2 regulation of sodium channel subunit expression and has been studied extensively studied. However, less attention has been given to the role of the ubiquitin-like protein Nedd8. Here we show that Nedd8 plays an important role in the ubiquitination of ENaC in alveolar epithelial cells. We report that the Nedd8 pathway is redox-sensitive and that under oxidizing conditions Nedd8 conjugation to Cullin-1 is attenuated, resulting in greater surface expression of α-ENaC. This observation was confirmed in our electrophysiology studies in which we inhibited Nedd8-activating enzyme using MLN4924 (a specific Nedd8-activating enzyme inhibitor) and observed a marked increase in ENaC activity (measured as the product of the number of channels (N) and the open probability (Po) of a channel). These results suggest that ubiquitination of lung ENaC is redox-sensitive and may have significant implications for our understanding of the role of ENaC in pulmonary conditions where oxidative stress occurs, such as pulmonary edema and acute lung injury.

Neddylation is a ubiquitination-like pathway. It has been reported that neddylation inhibition with the pharmacological agent MLN4924 potently uppresses lipopolysaccharide (LPS)-induced proinflammatory cytokine production, including tumor necrosis factor (TNF)-α and interleukin (IL)-6, by preventing the degradation of phosphorylated inhibitor of κB (p-IκB) in macrophages. However, whether neddylation serves a similar role in neutrophils remains unknown. In the present study MLN4924 treatment led to the accumulation of P-IκBα in neutrophils as well as the decreased production of TNF-α, IL-6 and IL-1β in response to LPS, in a dose-dependent manner. The viability of neutrophils was only marginally affected in the same conditions, without statistical significance. Furthermore, the nuclear factor (NF)-κB inhibitor JSH-23 mimicked the effects of MLN4924 in neutrophils, and the inhibitory effects of MLN4924 on LPS-induced proinflammatory cytokine production diminished in the presence of JSH-23. Thus, the results of the present study suggest that neddylation inhibition suppresses neutrophil function by suppressing the NF-κB signaling pathway.