| Objectives The current study is aimed to investigate the role of copper proteomics on neurotoxicity in hippocampus of rats following lead exposure in order to provide a theoretical basis for further revealing the mechanism of neurotoxicity and screening the biomarkers of lead induced neurotoxicity.Methods 1 Experiment animal treatment: 30 SPF male F344 rats were randomly divided into control and lead exposure group. Rats were received 0.03% sodium acetate in control group; and 0.03% lead acetate in lead acetate group in drinking water for 9 weeks. 2Morris water maze was used to measure neurobehavioral.4 Inductively coupled plasma mass spectrometry(ICP-MS) analysis was applied to measure lead,copper content.5ELISA was used to detect advanced glycation end products content, hydrogen peroxide content and the ability to inhibit the hydroxyl radical.6 i TRAQ labeling technique combined with liquid chromatography and tandem mass spectrometry was used to measure proteomics and bioinformatics analysis was performed.7 Western blot was used to detect ATP7 A,CTR1 protein expression levels.8 Cu/Zn SOD,ceruloplasmin CP activity were measured by using kits. 9 Real-time quantitative PCR was used to determine m RNA expression of copper transporter protein(atp7a, atp7 b, ctr1, dmt1), copper chaperone protein(atox1, cox17) and copper storage protein(mt1a, mt2 a, mt3).SPSS17.0 sofware was used to perform statistical data analysis and P<0.05 was statistically significant.Results 1 Morris water maze test results showed that escape latency of rats in lead exposure group was longer and the times crossing the platform was shorter than that in the control group.2 Effect of lead exposure on hippocampus pathological change:neuron cells in hippocampus in lead-exposed rats were showed disorder, nuclear condensation, and even apoptosis.3 copper content of rats hippocampus in lead-exposure group was 3.71 folds and 2.87 folds than that in control group.4 The content of hydrogen peroxide and advanced glycation end products in the hippocampus of lead exposure group were greatly increased, and the difference were statistically significant. The ability to inhibit the hydroxyl radical reduced than the normal rats.5 5166 proteins were indentified in all groups.A total of 312 proteins were showed significantly different based on 1.2 times differences and P value of less than 0.05.Among them,there are 16 copper related proteins up-regulated and 12 proteins were down-regulated.6 Western blot showed that CTR1protein expression increased, and ATP7 A protein expression was decreased.7 Cu/Zn-SOD and CP activity of hippocampus in lead exposure decreased 32.75% and 61.08% than those in control group. 8 Compared with the control group, atp7 a,atp7b,dmt1 m RNA expression of hippocampus in rats of the lead-exposed group were lower and ctr1 m RNA expression increased.Copper chaperones atox1 and cox17 m RNA expression of hippocampus in rats of the lead-exposed group also increased. Mt1 a,mt2a,mt3 m RNA expression were decreased,and the difference was statistically significant.Conclusions Lead exposure does result in copper accumulation in rat hippocampus with oxidative damage increase.Proteomics showed, the function of 16 up-regulated and 12down-regulated copper-associated protein were related to copper transportation and clearance,which may involved in the lead neurotoxicity. |
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