Abstract 2028 Long-term O-GlcNAc elevation effects brain mitochondrial activity and reactive oxygen species production

Mitochondria are dynamic organelles that play essential roles in key metabolic activities from energy production to cellular signaling. Mitochondrial adaptation to stress and metabolic demands relies on a range of reversible post translation modifications (PTMs). These modifications are linked to apoptosis, oxidative phosphorylation, hypoxia response, and mitochondrial function and biogenesis. The mitochondrial proteome can be phosphorylated, O-GlcNAcyated, or both. O-GlcNAcylation, a single sugar post-translational modification, regulated by O-GlcNAcase (OGA) and O-GlcNAc transferase (OGT) enzymes, which dynamically remove and add the sugar respectively. Nevertheless, our understanding on PTM alterations of specific mitochondrial protein that affect mitochondrial function remains unknown. Here, we performed multiplexed quantitative mass spectrometry-based proteomics to chart the remodeling of the mouse brain mitochondrial proteome and phosphoproteome during the long-term O-GlcNAcase inhibition using Thiamet G (TMG). Interestingly, our analyses reveal that TMG has gender specific effects on male with little change in female. Mitochondrial electron transport chain (ETC) proteins were significantly decreased in TMG treated male brain's mitochondria compared to saline with almost no change in female. There are also significant functional alterations on complexes I, II, and IV in male with no change in female. Phosphoproteome data reveals alterations on phosphorylation sites on the ETC. Additionally, mitochondrial proteome identified significant elevations in antioxidant proteins in male with significant reduction in female TMG treated compared to control. Consistently, mitochondrial hydrogen peroxide (H2O2) and superoxide (O2) were significantly decreased in male, while they are increased in female. Collectively, our work indicates that OGA inhibition has a profound effect on cellular energetics, ROS production, and metabolic output in gender specific manner. Funded by National Institute of Health #R01AG064227.