Systemic inhibition of neddylation by 3-day MLN4924 treatment regime does not impair autophagic flux in mouse hearts and brains.

Beyond helping the cell survive from energy starvation via self-eating a portion of cytoplasm, macroautophagy is also capable of targeted removal of defective organelles or cytoplasmic aberrant protein aggregates, thereby playing an important role in quality control in the cell. Impaired or suppressed macroautophagy activity is associated with the progression from a large subset of heart diseases to heart failure and with the development of the vast majority of, if not all, neurodegenerative diseases, the leading causes of death and disability in humans. Hence, a better understanding of the impact of existing and upcoming pharmacotherapies on macroautophagy in the heart and brain will undoubtedly benefit the search for safer and more effective treatment to improve human health. Neddylation is a recently recognized posttranslational modification process that modifies a subset of cellular proteins and is, by virtue of regulating Cullin-RING ligases, essential to ~20% ubiquitin-proteasome system (UPS)-mediated protein degradation. MLN4924 (Pevonedistat), a specific inhibitor of neddylation that promises to become a new anti-malignancy agent, is capable of inhibiting UPS-mediated progression of the cell cycle and activating macroautophagy in cancer cells. However, no reported study has tested the impact of systemic inhibition of neddylation on autophagic activity in a post-mitotic organ such as the heart and brain. This study was conducted to fill this gap. Sixteen GFP-LC3 transgenic mice of mixed sexes were divided equally into either MLN4924-treated or vehicle-treated groups and were treated respectively with MLN4924 (30 mg/kg,