Deep Succinylproteomics of Brain Tissues of Intracerebral Hemorrhage with Inhibition of Toll-like Receptor 4 Signaling

The details of Toll-like receptor (TLR) 4 signaling affects protein succinylation in intracerebral hemorrhage (ICH) brains remains completely unclear. In this study, we constructed mice ICH models to investigate the changes in ICH-associated brain protein succinylation with the treatment of TLR4 antagonist, TAK242, using a high-resolution mass spectrometry-based, quantitative succinyllysine proteomics approach. We characterized a concentration of approximately 6700 succinylation events and quantified approximately 3500 sites, highlighting 139 succinyllysine site changes in 40 pathways. Further analysis showed that TAK242 treatment induced an increase in 29 succinyllysine sites of 28 succinylated proteins and reduction of 24 succinyllysine sites on 23 succinylated proteins in ICH brains. Both the TAK242 treatment induced hypersuccinylated and hyposuccinylated proteins in ICH brains were mainly located in mitochondria and cytoplasm. GO analysis showed that TAK242 treatment induced changes in ICH-associated succinylated proteins were mostly located in synapse, membrane, vesicle, etc., and enriched in many processes, such as metabolism, synapse, myeline, etc.. KEGG analysis showed that TAK242 induced downregulation of succinylation was significantly linked to fatty acid metabolism and lysosome. Moreover, a combination analysis of our succinylproteomic data with previously published transcriptome data identified that most of the differentially succinylated proteins induced by TAK242 treatment were mainly distributed into neurons, astrocytes and endothelial cells; and 7 and 3 of these succinylated proteins significantly high express in neurons and astrocytes, respectively. In conclusion, our analyses uncover a number of TLR4 signaling affected succinylation processes and pathways in mouse ICH brains and provide new insights for understanding ICH pathophysiological processes. Data are available via ProteomeXchange with identifier PXD025622.