Yu-Gang Jiang

Academy of Military Medical Sciences, T’ien-ching-shih, Tianjin Shi, China

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Publications (6)8.24 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: An experiment was performed to observe the changes in Raf-1 kinase/mitogen-activated protein kinase ERK (MEK)/extracellular signal-regulated kinase (ERK) signaling pathways in cultured hippocampal neurons and its correlation with neurons apoptosis induced by intracellular zinc depletion. Cultured hippocampal neurons were exposed to a cell membrane-permeant zinc chelator TPEN (2 µM), and to TPEN plus zinc sulfate (5 µM) for 24 h. Cultures were then processed to detect neuronal viability by the methyl thiazolyl tetrazolium assay, while apoptosis rate was simultaneously observed by the flow cytometric analysis. Caspase-3, Raf-1, pMEK, pERK1/2, and pCREB protein levels were examined by Western blot assays. The viability in TPEN-incubated neurons was notably decreased, apoptosis rate and expression of caspase-3 significantly increased compared to untreated controls. The significant down-regulation of Raf/MEK/ERK signaling pathway and expression of pCREB were decreased in TPEN-treated neurons. Co-addition of zinc almost completely reversed TPEN-induced alterations described. The results demonstrated zinc-modulated apoptosis and the expression of Raf/MEK/ERK at the protein level in hippocampal neurons. It is possible that zinc depletion-induced apoptosis in cultured hippocampal neurons may be relevant to the changes of Raf/MEK/ERK signaling pathway.
    Nutritional Neuroscience 01/2012; 15(1):18-24. · 1.65 Impact Factor
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    ABSTRACT: An experiment was conducted to investigate whether intracellular zinc depletion can actually change expression of voltage-dependent anion channel 1 (VDAC1) and VPAC2 in cultured hippocampal neurons as well as their significance. Hippocampal neurons were obtained by primary culture from hippocampus of newborn Wistar rats. Cultured hippocampal neurons were exposed to a cell membrane-permeable zinc chelator N,N,N',N'-tetrakis (2-pyridyl methyl) ethylenediamine (TPEN) (2 µM), and to TPEN plus zinc sulfate (5 µM) for 1 or 24 hours. Cultures were then processed to detect neuronal injury by lactate dehydrogenase (LDH) assay, intracellular Ca(2+) with the fluorescent probe fluo-3/AM, reactive oxygen species (ROS) generation using 2',7'-dichlorofluorescein diacetate (DCFH-DA) assay, nuclear morphology by Hoechst 33342, VDAC1, and VDAC2 protein levels by western blot, and VDAC1 and VDAC2 mRNA levels by RT-PCR. The results demonstrated that exposure of hippocampal neurons to TPEN (2 µM) for 24 hours induced notably neuronal injury, significantly increased the number of apoptotic nuclei, up-regulated the expression of VDAC1 protein level and down-regulated the expression of VDAC2 protein level. Significant down-regulation of mRNA levels for VDAC1 and VDAC2 were observed in TPEN-treated neurons. Co-addition of zinc almost completely reversed TPEN-induced neuronal injury and above alterations in VDAC1 and VDAC2 protein levels and mRNA levels. Present results implicate a possibility that up-regulation of VDAC1 and down-regulation of VDAC2 may participate in hippocampal neuron injury induced by zinc deficiency.
    Nutritional Neuroscience 03/2011; 14(2):80-7. · 1.65 Impact Factor
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    ABSTRACT: An experiment was performed to observe changes of mitogen-activated protein kinase ERK (MEK)/extracellular signal-regulated kinase (ERK) signaling pathways in the hippocampus of zinc-deficient (ZD) rats and the correlation with cognitive dysfunction. Forty-four male weanling Wistar rats were randomly assigned to ZD (n = 22) and control (pair-fed, n = 22) groups. After a 4-week treatment, Y-maze was used to test the spatial memory of the rats. The long-term potentiation (LTP) in rat hippocampal dentate gyrus was observed simultaneously. pMEK, pERK1/2, and pCREB protein levels were examined by Western blot assays. The results demonstrated that the latency period in Y-maze was significantly shorter for the ZD rats. LTP amplitude in the ZD group decreased significantly compared with the control group. pMEK, pERK1/2, and pCREB protein expression of hippocampus in the ZD group decreased significantly. The results implicated a possibility that zinc deficiency-induced cognitive and synaptic impairment may be relevant to the MEK/ERK signaling pathway.
    Nutritional Neuroscience 03/2011; 14(2):45-50. · 1.65 Impact Factor
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    ABSTRACT: Relationships between hyperhomocysteinemia (HHE) and neurodegenerative diseases have been widely studied. However, the impact of serum total homocysteine (tHcy) levels on cognitive function has not been confirmed. C677T polymorphisms in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene have impacts on tHcy level; it is suspected to influence cognitive function, but only few investigations have assessed its effects on non-dementia adults and the results have been controversial. Moreover, there is no report about Chinese subjects. In the present study, we determined C677T/MTHFR genotype, serum tHcy concentration and cognition in 182 nondemented subjects aged 55-88 years to probe the associations between MTHFRC677T mutation, increased tHcy levels and decreased cognitive function in a northern city in China. A serum tHcy level > or = 16 micromol/l was deemed HHE. Cognitive function was assessed by the Mini Mental State Examination (MMSE) and Basic Cognitive Aptitude Tests (BCAT). Results showed that: (i) subjects with the T allele had higher serum tHcy levels than those without, especially in lower folate status; (ii) T allele and CT/TT genotype frequencies in subjects with HHE were higher than in non-HHE subjects (P < 0.05); and (iii) serum tHcy level was inversely related to total BCAT score (P < 0.05) but MTHFR677 C to T polymorphism had no association with it. Our results confirmed that the MTHFR 677 C to T mutation, especially in lower serum folate concentration status, results in the increase of serum tHcy levels which is bad for cognitive function and indicates that higher serum folate level is of benefit in keeping lower serum tHcy level and better cognitive function. The results provide some valuable clues for individualized nutrition intervention of HHE and cognition decline in the middle-aged and the elderly.
    Nutritional Neuroscience 08/2010; 13(4):175-82. · 1.65 Impact Factor
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    ABSTRACT: To investigate the protective effect of blueberry extract (BE, 25% anthocyanins) against oxidative damage in primary cultures of rat hippocampal neurons induced by H2O2. Rat hippocampal neurons were randomly assigned to control group, H2O2 group and BE pretreatment groups, BE at six different doses (0.01, 0.1, 1.0, 10.0, 20.0 and 40 microg/ml) and then exposed to 50 micromol/L H2O2 for twenty-four hours. To selecte the most fittest concentration of BE by testing viability of neurons and activity of LDH. Then MDA concentration, SOD activity and neuronal apoptosis were(checked) measured. (1) Compared with H2O2 group, the hippocampal cell viabilities in the 0.1, 1.0 and 10 microg/ml BE groups were significantly increased from 57.44% to 78.42%, 87.71% and 72.40% separately. The activity of LDH in BE groups at varied concentrations (0.1, 1.0 and 10 microg/ml) was significiantly lower than that in H2O2 group. It was found that 1 microg/ml BE had the furthest protective effect against oxidative damage in primary cultures of rat hippocampal neurons induced by H2O2. (2) The concentration of MDA and the rate of neuronal apoptosis of BE group (1 microg/ml) were much lower than H2O2 group, while SOD activity was much higher. Proper dose of BE has remarkable protective effect against oxidative stress in primary cultures of rat hippocampal neurons induced by H2O2, the mechanism may be related to decreasing the neuronal apoptosis and enhancing the antioxidation of hippocampal neurons.
    Zhongguo ying yong sheng li xue za zhi = Zhongguo yingyong shenglixue zazhi = Chinese journal of applied physiology 02/2010; 26(1):51-4.
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    ABSTRACT: Zinc deficiency has been associated with impaired learning and memory function in animals and human beings. However, the molecular mechanisms remain obscure. In light of evidence that ubiquitin C-terminal hydrolase L1 (Uch-L1) and cAMP-responsive element-binding protein (CREB) are required for synaptic and memory function and the possible regulation of CREB by Uch-L1, this present study was conducted to investigate the effect of zinc depletion on Uch-L1 protein expression and on Uch-L1 and CREB mRNA expression in cultured hippocampal neurons. Cultured hippocampal neurons were exposed to a cell membrane-permeant zinc chelator TPEN (2 microM), and to TPEN plus zinc sulphate (5 microM) for 24 h. Cultures were then processed to detect neuronal injury by lactate dehydrogenase (LDH) assay, Uch-L1 protein levels by Western blot, and Uch-L1 and CREB mRNAs levels by RT-PCR. The LDH release rate in TPEN-incubated neurons was notably increased compared to non-treated controls. Significant down-regulation of Uch-L1 protein level and mRNA levels for Uch-L1 and CREB were observed in TPEN-treated neurons. Co-addition of zinc almost completely reversed TPEN-induced neuronal injury and the alterations in Uch-L1 and CREB expression. The results demonstrated that zinc modulated the expression of Uch-L1 and CREB at the protein and/or transcription levels in hippocampal neurons, which implies that down-regulation of both Uch-L1 and CREB might participate in memory dysfunction induced by zinc deficiency.
    Nutritional Neuroscience 07/2008; 11(3):96-102. · 1.65 Impact Factor

Publication Stats

10 Citations
8.24 Total Impact Points

Institutions

  • 2011–2012
    • Academy of Military Medical Sciences
      T’ien-ching-shih, Tianjin Shi, China
    • Sichuan University
      • Department of Nutrition and Food Hygiene
      Chengdu, Sichuan Sheng, China
  • 2010
    • Tianjin Institute of Health And Environmental Medicine
      T’ien-ching-shih, Tianjin Shi, China