Hippocampal phosphoproteomics of F344 rats exposed to 1-bromopropane

In Vitro Exposure to Glucose Alters the Expression of Phosphorylated Proteins in Platelets

Diabetes mellitus (DM) is a pro-thrombotic state that can potentially cause serious cardiovascular complications. Platelet hyperactivation plays an important role in these pathological processes, however there is little or no information on the effect of hyperglycemia on platelet proteins. The aim of this study was to identify the molecular targets associated with platelet reactivity under hyperglycemia. Towards this goal, we examined the effects of the exposure of platelets to 1 and 2 h glucose (300 mg/dL) and control (vehicle and osmolality control using mannitol) on platelet proteins (n = 4 samples per group) using two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) combined with MALDI-TOF/TOF tandem mass spectrometry. Two-hour exposure to glucose significantly up-regulated the expression of ATP synthase subunit beta, filamin-A, and L-lactate dehydrogenase A chain in platelets. Pro-Q Diamond staining confirmed the effect of 2 h glucose on vinculin, heat shock protein HSP 90-alpha, filamin-A, and fructose-bisphosphate aldolase A (platelet phosphorylated proteins). The identified proteins are involved in various cellular processes and functions and possibly in platelet reactivity under hyperglycemic conditions.

Biomarkers of exposure and effect in the serum and urine of rats or workers exposed to 1-bromopropane

Extensively used in several industries in China as a cleaning agent, 1-bromopropane (1-BP) has significant adverse effects on the central nervous system. However, neither its mechanism of action nor sensitive biomarkers related to it have been determined thus far. In this study, animal experiments and occupational surveys were performed to explore the typical exposure and effect biomarkers of neurotoxicity induced by 1-BP. Male Wistar rats were exposed to 0, 500, or 1000 ppm of 1-BP followed by pathological and biomarker analyses. An epidemiological survey was conducted on 71 workers each from 1-BP exposed and control groups. Serum and urine samples were collected for biomarker testing. cNSE represents neuron-specific enolase (NSE) in the cerebral cortex, where as sNSE represents NSE in the serum; similar terminology applies to S-100β, and cyclooxygenase-2 (COX-2). In rats exposed to 1000 ppm 1-BP, pathological changes were observed in Purkinje cells, lumbar gray matter, and tibiofibular nerve, while levels of cNSE, cS-100β, cCOX-2, sS-100β, and sCOX-2 were significantly elevated at different time checkpoints. In the 500 ppm group, cCOX-2, sNSE, and sCOX-2 levels were significantly elevated at different time checkpoints. 1-BP and N-acetyl-S-(n-propyl)-L-cysteine (AcPrCys) were detected in rat urine, and there was a correlation between the level of sNSE or sCOX-2 and AcPrCys in the 500 ppm group. In the occupational epidemiological study, a significant correlation between AcPrCys and exposure concentration was also detected. The findings of this study indicated that AcPrCys was a sensitive exposure biomarker of 1-BP in rats as well as occupational populations.

Proteomic analysis of liver proteins of mice exposed to 1,2-dichloropropane

1,2-Dichloropropane (1,2-DCP) is recognized as the causative agent for cholangiocarcinoma among offset color proof-printing workers in Japan. The aim of the present study was to characterize the molecular mechanisms of 1,2-DCP-induced hepatotoxic effects by proteomic analysis. We analyzed quantitatively the differential expression of proteins in the mouse liver and investigated the role of P450 in mediating the effects of 1,2-DCP. Male C57BL/6JJcl mice were exposed to 0, 50, 250, or 1250 ppm 1,2-DCP and treated with either 1-aminobenzotriazole (1-ABT), a nonselective P450 inhibitor, or saline, for 8 h/day for 4 weeks. Two-dimensional difference in gel electrophoresis (2D-DIGE) combined with matrix-assisted laser-desorption ionization time-of-flight mass spectrometry (MALDI-TOF/TOF/MS) was used to detect and identify proteins affected by the treatment. PANTHER overrepresentation test on the identified proteins was conducted. 2D-DIGE detected 61 spots with significantly different intensity between 0 and 250 ppm 1,2-DCP groups. Among them, 25 spots were identified by MALDI-TOF/TOF/MS. Linear regression analysis showed significant trend with 1,2-DCP level in 17 proteins in mice co-treated with 1-ABT. 1-ABT mitigated the differential expression of these proteins. The gene ontology enrichment analysis showed overrepresentation of proteins functionally related to nickel cation binding, carboxylic ester hydrolase activity, and catalytic activity. The results demonstrated that exposure to 1,2-DCP altered the expression of proteins related with catalytic and carboxylic ester hydrolase activities, and that such effect was mediated by P450 enzymatic activity.