TMT-based proteomics analysis of the cerebral cortex of TauT knockout rats

A global view on quantitative proteomic and metabolic analysis of rat livers under different hypoxia protocols

Hypobaric hypoxia causes altitude sickness and significantly affects human health. As of now, focusing on rats different proteomic and metabolic changes exposed to different hypoxic times at extreme altitude is blank. Our study integrated in vivo experiments with tandem mass tag (TMT)- and gas chromatography time-of-flight (GC-TOF)-based proteomic and metabolomic assessments, respectively. Male Sprague-Dawley rats were exposed to long-term constant hypoxia for 40 days or short-term constant hypoxia for three days, and their responses were compared with those of a normal control group. Post-hypoxia, serum marker assays related to lipid metabolism revealed significant increases in the levels of low-density lipoprotein (LDL), triglycerides (TG), and total cholesterol (TC) in the liver. In contrast, high-density lipoprotein (HDL) levels were upregulated in the long-term constant hypoxia cohorts and were significantly reduced in the short-term constant hypoxia cohorts. Furthermore, metabolic pathway analysis indicated that glycerolipid and glycerophospholipid metabolisms were the most significantly affected pathways in long-term hypoxia group. Subsequently, RT-qPCR analyses were performed to corroborate the key regulatory elements, including macrophage galactose-type lectin (MGL) and Fatty Acid Desaturase 2 (FADS2). The results of this study provide new information for understanding the effects of different hypobaric hypoxia exposure protocols on protein expression and metabolism in low-altitude animals.

Study on the underlying molecular mechanism of benzene-induced nervous system damage in mice based on tandem mass tag (TMT) proteomics

Benzene is known to be a common toxic industrial chemical, and prolonged benzene exposure may cause nervous system damage. At present, there were few studies on benzene-induced neurological damage. This research aimed to identify the protein biomarkers to explore the mechanism of nervous system damage caused by benzene. We established a benzene poisoning model of C57 mice by gavage of benzene-peanut oil suspension and identified differentially expressed proteins (DEPs) in brain tissue using tandem mass tag (TMT) proteomics. The results showed a significant weight loss and decrease in leukocyte and neutrophil counts in benzene poisoning mice compared to the control group. We also observed local cerebral oedema and small vessel occlusion in the cerebral white matter of benzene poisoning mice. TMT proteomic results showed that a total 6,985 proteins were quantified, with a fold change (FC) > 1.2 (or < 1/1.2) and P value <0.05 were considered as DEPs. Compared with the control group, we identified 43 DEPs, comprising 14 upregulated and 29 downregulated proteins. Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis results showed that the candidate proteins were mainly involved in cholesterol metabolism, complement and coagulation cascades, african trypanosomiasis, PPAR signaling pathway, and vitamin digestion and absorption. Three proteins, 2-hydroxyacylsphingosine 1-beta-galactosyltransferase (UGT8), Apolipoprotein A-I (APOA1) and Complement C3 (C3) were validated using immunoblotting and immunohistochemical. In conclusion, our study preliminarily investigated the mechanism of benzene toxicity to the nervous system by analyzing DEPs changes in the brain.