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ABSTRACT: The effect of lead (Pb) on spatial memory and hippocampal long-term potentiation (LTP) as a key risk factor has been widely recognized and the oxidative damage has been proposed as a possible mechanism of lead neurotoxicity. Selenium (Se) is a nutritionally essential trace element with known antioxidant potential. In this study we investigated the effect and the underlying mechanisms of Se supplementary on Pb induced cognition and synaptic plasticity impairment. Lactating Sprague-Dawley rats (SD rats) were randomly divided to four groups: 0ppm lead acetate (Pb); 0ppm Pb and 0.2ppm sodium selenite (Se); 100ppm Pb; 100ppm Pb and 0.2ppm Se. Lactating rats were treated with or without Pb and/or Se throughout lactation until weaning. The levels of hippocampal LTP, the spatial memory, the apoptosis of hippocampal neurons, the levels of lactate dehydrogenase (LDH) release, and the serum level of superoxide dismutase (SOD) and malondialdehyde (MDA) were assayed. It had been observed that in Pb group the spatial memory, the induce level of LTP, the serum SOD level decreased, the LDH release level, the neurons apoptosis level, the serum MDA level increased, while in the Se supplements groups, the spatial memory, the induce level of LTP increased significantly. Compared with the Pb group, Se supplements shown down regulated the level of LDH, the neurons apoptosis and the serum MDA, and up regulated the level of serum SOD. We could draw the conclusion that Se supplements could alleviate toxic effect of lead on hippocampal LTP and spatial memory. The treated with selenium around 0.2ppm may protect against spatial memory dysfunction induced by lead exposure.
NeuroToxicology 03/2013; · 3.10 Impact Factor
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ABSTRACT: Exposure of Lead (Pb), a known neurotoxicant, can impair spatial learning and memory probably via impairing the hippocampal long-term potentiation (LTP) as well as hippocampal neuronal injury. Activation of hippocampal microglia also impairs spatial learning and memory. Thus, we raised the hypothesis that activation of microglia is involved in the Pb exposure induced hippocampal LTP impairment and neuronal injury. To test this hypothesis and clarify its underlying mechanisms, we investigated the Pb-exposure on the microglia activation, cytokine release, hippocampal LTP level as well as neuronal injury in in vivo or in vitro model. The changes of these parameters were also observed after pretreatment with minocycline, a microglia activation inhibitor. Long-term low dose Pb exposure (100 ppm for 8 weeks) caused significant reduction of LTP in acute slice preparations, meanwhile, such treatment also significantly increased hippocampal microglia activation as well as neuronal injury. In vitro Pb-exposure also induced significantly increase of microglia activation, up-regulate the release of cytokines including tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β) and inducible nitric oxide synthase (iNOS) in microglia culture alone as well as neuronal injury in the co-culture with hippocampal neurons. Inhibiting the microglia activation with minocycline significantly reversed the above-mentioned Pb-exposure induced changes. Our results showed that Pb can cause microglia activation, which can up-regulate the level of IL-1β, TNF-α and iNOS, these proinflammatory factors may cause hippocampal neuronal injury as well as LTP deficits.
PLoS ONE 01/2012; 7(8):e43924. · 4.09 Impact Factor
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ABSTRACT: To study the effect of chronic multiple stress on learning and memory, and the expression and activation of cerebral extracellular signal-regulated protein kinase (ERK) 1/2 of rats in vivo.
Ninety male SD rats were divided randomly into control group and stress group. Rats in stress group were stressed everyday by one of the seven stressors including cold exposure, foot shock, white noise, restraint, tail hung up, sleep deprivation, and level shake, and then the ability of learning and memory was determined by Morris water maze test. Serum corticosterone (CORT) level was determined by radioimmunoassay kit. Western blot was performed to determine the expression and phosphorylation of ERK in hippocampus and prefrontal cortex of the brain.
The escape latencies of stressed rats were substantially longer than those of the controls in the water maze test (P < 0.01) except a transient recovery at the end of the third week after the stress. The stress also resulted in significantly higher serum CORT level and decreased P-ERK level in hippocampus and prefrontal cortex (PFC) (P < 0.01). Similarly, transient elevation of both CORT and P-ERK levels were observed at the end of the third week.
Chronic multiple stress can lead to impaired learning and memory by decreasing the phosphorylation of ERK in the hippocampus and PFC. The partial recovery of learning and memory, CORT and P-ERK levels at the end of the third week may due to the adaptation of the rats to stressors.
Zhongguo ying yong sheng li xue za zhi = Zhongguo yingyong shenglixue zazhi = Chinese journal of applied physiology 02/2011; 27(1):33-6.
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Ying-Yong Zhao,
Xuefeng Shen,
Xu Chao,
Charlene C Ho,
Xian-Long Cheng,
Yongmin Zhang,
Rui-Chao Lin,
Ke-Jun Du, Wen-Jing Luo,
Jing-Yuan Chen,
Wen-Ji Sun
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ABSTRACT: Mushrooms have been used in Asia as traditional foods and medicines for a long time. Ergosta-4,6,8(14),22-tetraen-3-one (ergone) is one of the well-known bioactive steroids, which exists widely in various medicinal fungi such as Polyporus umbellatus, Russula cyanoxantha, and Cordyceps sinensis. Ergone has been demonstrated to possess cytotoxic activity. However, the molecular mechanisms by which ergone exerts its cytotoxic activity are currently unknown.
In the present study, ergone possessed a remarkable anti-proliferative activity toward human hepatocellular carcinoma HepG2 cells. We assayed the cell cycle by flow cytometry using PI staining; investigated the exposure of phosphatidylserine at the outer layer of the cytoplasmic membrane by the FITC-annexin V/PI staining; observed the nuclear fragmentation by Hoechst 33258 staining and studied the protein expression of Bax, Bcl-2, p-53, procaspase-3, -8, -9, PARP and cleaved PARP by Western blotting analysis.
Cells treated with ergone showed typical markers of apoptosis: G2/M cell cycle arrest, chromatin condensation, nuclear fragmentation, and phosphatidylserine exposure. Furthermore, PARP-cleavage; activation of caspase-3, -8, -9; up-regulation of Bax and down-regulation of Bcl-2 were observed in HepG2 cells treated with ergone, which show that both the intrinsic and extrinsic apoptotic pathways are involved in ergone-induced apoptosis in HepG2 cells. Ergosta-4,6,8(14),22-tetraen-3-one induces G2/M cell cycle arrest and apoptosis in HepG2 cells in a caspase-dependent manner.
In this study, we reported for the first time that ergone-induced apoptosis through activating the caspase. These results would be useful for the further utilization of many medicinal fungi in cancer treatment.
Biochimica et Biophysica Acta 01/2011; 1810(4):384-90. · 4.66 Impact Factor
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ABSTRACT: Previous research has demonstrated that paradoxical sleep has a key role in learning and memory, and sleep deprivation interferes with learning and memory. However, the mechanism of memory impairment induced by sleep deprivation is poorly understood. The present study investigated the effect of paradoxical sleep deprivation (PSD) on spatial learning and memory using the Morris Water Maze. Effects of PSD on CA1 pyramidal neurons in hippocampus were also examined. PSD impaired spatial learning of rats. PSD induced translocation of Bax to mitochondria and cytochrome c release into the cytoplasm, and decreased the membrane excitability of CA1 pyramidal neurons, effects which may contribute to the deficits in learning behavior. These results may partially explain the mechanism of the effect of PSD on learning. Modulating the excitability of hippocampal neurons and protecting mitochondrial function are possible targets for preventing the effects of paradoxical sleep deprivation.
Brain Research 10/2008; 1230:224-32. · 2.73 Impact Factor
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ABSTRACT: To study the effect of acute fear stress on emotional behaviors, Hormone levels, and the expression and activation of cerebra Erk1/2 of rats in vivo.
Fourty eight male SD rats were divided randomly into control group and stress group. Rats of stress group received 30 min' s acute stress including foot shock and white noise, and then the emotional behaviors were observed. The hormone level in plasm and brain was determined by spectrophotofluorometry and radioimmunoassay kit. In the following experiments, Western blot was performed to determine the expression and phosphorylation of extracellular signal-regulated protein kinase (Erk) of four different regions of the brain.
Rats tested after acute fear stress displayed substantial decreases in open-field activity, increases in resistance to capture, and increases in fright reaction (P < 0.01). The stress also resulted in significantly higher plasmic and cerebral noradrenaline, corticosteroid, 5-hydroxytryptamine levels, and lower adrenomedulin level in comparison with the control (P < 0.01) after stress. At the time point of 0 min and 30 min after stress, the phosphorylation of Erk1/2 were increased in all four brain regions examined (hippocampus, striatum, prefrontal cortex and cerebellum).
Acute fear stress can induce abnormalities of emotional behaviors, such as behavioral habits, anxiety and defense, startle and delayed adaptation to startle, as well as the alteration of hormone levels. The phosphorylation of Erk1/2 may play a role in the abnormality of emotional behaviors of rats induced by acute fear stress.
Zhongguo ying yong sheng li xue za zhi = Zhongguo yingyong shenglixue zazhi = Chinese journal of applied physiology 08/2007; 23(3):270-4.
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ABSTRACT: To clone full-length human lipopolysaccharide responsive gene(hlrp) and predict its function by bioinformatics analysis; to observe full-length hlrp protein and quantify its relative gene expression in four cell lines.
Total RNA was extracted from LPS-stimulated human embryonic kidney cells HEK293 and the full-length hlrp was obtained by RT-PCR. Function of hlrp was predicted by bioinformatics analysis with Internet and GenBank database. Expression full-length hlrp protein in HEK293, HepG2, HeLa and PDC was observed by laser scanning confocal fluorescence microscope and compared.
Full-length hlrp of 2 045 bp was amplified and sequenced. Leucine zipper was found in the hlrp series that may have an important function. hlrp gene have been mapped to a particular chromosome location in Xp22.2. Laser scanning confocal fluorescence microscope showed hlrp protein was expressed in the cell lines (HEK293, HepG2, HeLa and PDC).
hlrp has been successfully cloned and its function has been predicted. Expression of hlrp has been detected in 4 cell lines. Present result would provide data for the further study of hlrp.
Xi bao yu fen zi mian yi xue za zhi = Chinese journal of cellular and molecular immunology 06/2007; 23(5):420-2.
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ABSTRACT: The effect of compound nutrients on serum concentrations of the cytokines, such as interleukin (IL)-2, tumor necrosis factor-alpha (TNF-alpha) and interleukin (IL)-6 in immobilization and cold water-immersion stressed rat were investigated. Oral (gavage) administration of compound nutrients was found to attenuate the acute and chronic immobilization and cold water-immersion stress-induced increase in serum IL-6 level and decrease in IL-2 level. Compound nutrients exerted different effects on TNF-alpha level in two different models studied, with reduced serum TNF-alpha level in acute stress, while no significant effect in chronic stress. These results suggested that compound nutrients might be proposed as a possible candidate in the research or therapeutic modulation of stress-related disorders.
Cytokine 02/2007; 37(1):14-21. · 3.02 Impact Factor
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ABSTRACT: To express mouse lipopolysaccharide response protein (mLRP) and prepare rabbit anti-mLRP serum.
The predicted mouse lrp cDNA sequence was obtained by splicing homologous ESTs by comparing human lrp cDNA with mouse ESTs. Then the primers were designed. mlrp cDNA from NIH3T3 cells stimulated with lipopolysaccharide (LPS) was amplified by RT-PCR and was cloned into prokaryotic expression vector pTAT to construct recombinant expression vector pTAT-mlrp. The His-TAT-mLRP fusion protein was expressed in E. coli BL21(DE3) and was used to immunize the rabbits to get rabbit anti-mLRP serum. The anti-serum was purified by the acetone precipitation method. The specificity of the rabbit anti-mLRP serum was determined by Western blot.
The predicted length of mlrp cDNA was 1905 bp. The encoding region of the cloned mlrp cDNA, 1554 bp, was inserted into pTAT. The His-TAT-mLRP fusion protein was expressed successfully in E. coli. The rabbit anti-mLRP serum was prepared by immunizing the rabbit with mLRP protein.
The successful expression of mLRP and the preparation of rabbit anti-mLRP serum lays the foundation for further study of the function of mLRP.
Xi bao yu fen zi mian yi xue za zhi = Chinese journal of cellular and molecular immunology 06/2006; 22(3):371-3, 376.
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ABSTRACT: This study aimed at investigating the effects of vitamin D analogue EB1089 on the proliferation and apoptosis of hepatic carcinoma cells.
Hepatic carcinoma cell strain G(2) (Hep-G(2)) in which prominent vitamin D receptor (VDR) mRNA could be expressed and the cell strain T (HCC-T) negative in VDR gene expression were incubated in culture media with 100 nmol/L, 10 nmol/L and 1 nmol/L EB1089 for 2 d, 4 d and 6 d, respectively. Survival and proliferation of the cells were detected by blue tetrazolium colorimetric test and plate clone-forming test, the VDR mRNA expression was determined by reverse transcription-polymerase chain reaction (RT-PCR) and apoptosis of the cells was detected by flow cytometry (FCM) and electron microscopy.
EB1089 could inhibit the proliferation of hepatocellular cell line Hep-G(2) that expressed prominent vitamin D receptor mRNA, the inhibitory rate is 17.5% approximately 72.1%. On the other hand, EB1089 had no anti-proliferative effect on hepatocellular cell line HCC-T in which the gene expression of vitamin D receptors was negative. The electron microscope results showed that EB1089 could induce apoptosis of hepatocarcinoma cells and the percentages of apoptotic cells measured by flow cytometer was 21.4%. Cell cycle progression was blocked at G(1) phase with EB1089.
EB1089 could inhibit proliferation of human Hep-G(2), probably through VDR, and induce apoptosis of the cells.
Zhonghua yu fang yi xue za zhi [Chinese journal of preventive medicine] 12/2004; 38(6):415-8.
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ABSTRACT: The effect of compound nutrients on serum concentrations of the cytokines, such as interleukin (IL)-2, tumor necrosis factor-α (TNF-α) and interleukin (IL)-6 in immobilization and cold water-immersion stressed rat were investigated. Oral (gavage) administration of compound nutrients was found to attenuate the acute and chronic immobilization and cold water-immersion stress-induced increase in serum IL-6 level and decrease in IL-2 level. Compound nutrients exerted different effects on TNF-α level in two different models studied, with reduced serum TNF-α level in acute stress, while no significant effect in chronic stress. These results suggested that compound nutrients might be proposed as a possible candidate in the research or therapeutic modulation of stress-related disorders.
Cytokine.
