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ABSTRACT: Repeated morphine exposure can induce behavioral sensitization. There are evidences have shown that central gamma-aminobutyric acid (GABA) system is involved in morphine dependence. However, the effect of a GABAB receptor agonist baclofen on morphine-induced behavioral sensitization in rats is unclear.
We used morphine-induced behavioral sensitization model in rat to investigate the effects of baclofen on behavioral sensitization. Moreover, dopamine release in the shell of the nucleus accumbens was evaluated using microdialysis assay in vivo.
The present study demonstrated that morphine challenge (3 mg/kg, s.c.) obviously enhanced the locomotor activity following 4-day consecutive morphine administration and 3-day withdrawal period, which indicated the expression of morphine sensitization. In addition, chronic treatment with baclofen (2.5, 5 mg/kg) significantly inhibited the development of morphine sensitization. It was also found that morphine challenge 3 days after repeated morphine administration produced a significant increase of extracellular dopamine release in nucleus accumbens. Furthermore, chronic treatment with baclofen decreased the dopamine release induced by morphine challenge.
Our results indicated that gamma-aminobutyric acid system plays an important role in the morphine sensitization in rat and suggested that behavioral sensitization is a promising model to study the mechanism underlying drug abuse.
Behavioral and Brain Functions 05/2012; 8:20. · 2.13 Impact Factor
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ABSTRACT: There are few reports of the patterns of polymorphism in the non-coding regions of plant genomes. In this study, we explored
nucleotide diversity and linkage disequilibrium (LD) in 47 non-coding regions on chromosome 4 of wild and cultivated rice.
The cultivated rice retained about 70% of the diversity of wild rice, which was verified by coalescent simulations with one
population bottleneck for 198 combinations of duration and population sizes. Multi-locus likelihood analysis showed that the
severity of the bottleneck ranged from 2.25 to 3.33, with an average value of 2.70; i.e., the diversity found in the cultivated
rice could be explained by a founding population of 2,700 individuals if the initial domestication event occurred over a period
of 1,000years. LD decreased more rapidly in wild rice than in cultivated rice within 10kb, and the LD observed in cultivated
rice was increased at 100–140kb by comparison with wild rice. The patterns of LD indicated the possibility of a haplotype
block in cultivated rice but not in wild rice.
Plant Systematics and Evolution 04/2012; 281(1):97-106. · 1.34 Impact Factor
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Xifei Yang,
Yingzhi Jiang,
Jie Li,
Wen-Xu Hong,
Desheng Wu,
Xinfeng Huang, Haiyan Huang,
Li Zhou,
Lingqing Yang,
Jianhui Yuan,
Zhixiong Zhuang,
Jianjun Liu
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ABSTRACT: Trichloroethylene (TCE) is a common chemical pollutant that exists in air, soil, and drinking water. TCE exposure is known to cause severe hepatotoxicity; however, the mechanisms underlying TCE hepatotoxicity remain poorly understood. In a previous proteomics study, we found that TCE exposure up-regulated the expression of the inhibitor 2 of protein phosphatase 2A (I2PP2A), a potent and specific endogenous inhibitor of protein phosphatase (PP) 2A, in human hepatic L-02 cells. Here, we employed lentivirus-mediated RNA interference (RNAi) to knock down I2PP2A expression in L-02 cells and explored the potential role of I2PP2A in TCE-induced cytotoxicity. We found that TCE treatment of L-02 cells causes decreased cell viability, increased apoptosis and elevated I2PP2A mRNA and protein levels. TCE-treated L-02 cells were also found to have significantly reduced PP2A activity. Lentivirus-mediated I2PP2A knockdown partially prevented the decrease in viability and increased apoptosis induced by TCE treatment. Knockdown of I2PP2A in TCE-treated L-02 cells also suppressed the inhibition of PP2A activity and prevented caspase-3 activation. These data for the first time demonstrate that the up-regulation of I2PP2A could mediate, at least in part, TCE-induced liver cell toxicity through the inhibition of PP2A activity and caspase-3-mediated pathway, and suggest that I2PP2A may play a crucial role in mediating TCE hepatotoxicity.
Toxicology Letters 03/2012; 209(3):232-8. · 3.23 Impact Factor
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ABSTRACT: Aberrant epidermal growth factor receptor (EGFR) signaling is a common feature of multiple tumor types, including glioblastoma (GBM). As such, EGFR has emerged as an attractive target for antitumor therapy. In the present study, we sought to develop an immunotoxin capable of specifically targeting EGFR-expressing cells and mediating inhibition of cell growth and cell killing. The Luffin P1 (LP1) ribosome inactivating protein was chosen to generate a fusion protein, antiEGFR/LP1, based upon its potent protein synthesis inhibition and small size (5 kDa). LP1 was fused to the C-terminus of an anti-EGFR single-chain antibody (scFv). The recombinant antiEGFR/LP1 protein was expressed in Escherichia coli, and refolded and purified on an immobilized Ni(2+)-affinity chromatography column. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting analysis revealed that antiEGFR/LP1 was sufficiently expressed. Confocal microscopy and flow cytometry demonstrated that antiEGFR/LP1 bound specifically to EGFR-positive cells (U251), as almost no binding to EGFR-negative (Jurkat cells) was observed under identical time and dosage conditions. Finally, the MTT cell viability assay showed that antiEGFR/LP1 elicited obvious cytotoxicity toward EGFR-positive tumor cells. Collectively, these results suggest that antiEGFR/LP1 is biologically active and specific toward EGFR-positive tumor cells and may represent an effective EGFR-targeted cancer therapy.
Protein Expression and Purification 02/2012; 83(1):1-7. · 1.59 Impact Factor
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ABSTRACT: MOTIVATION: Pathway genes are considered as a group of genes that work cooperatively in the same pathway constituting a fundamental functional grouping in a biological process. Identifying pathway genes has been one of the major tasks in understanding biological processes. However, due to the difficulty in characterizing/inferring different types of biological gene relationships, as well as several computational issues arising from dealing with high-dimensional biological data, deducing genes in pathways remain challenging. RESULTS: In this work, we elucidate higher level gene-gene interactions by evaluating the conditional dependencies between genes, i.e. the relationships between genes after removing the influences of a set of previously known pathway genes. These previously known pathway genes serve as seed genes in our model and will guide the detection of other genes involved in the same pathway. The detailed statistical techniques involve the estimation of a precision matrix whose elements are known to be proportional to partial correlations (i.e. conditional dependencies) between genes under appropriate normality assumptions. Likelihood ratio tests on two forms of precision matrices are further performed to see if a candidate pathway gene is conditionally independent of all the previously known pathway genes. When used effectively, this is a promising approach to recover gene relationships that would have otherwise been missed by standard methods. The advantage of the proposed method is demonstrated using both simulation studies and real datasets. We also demonstrated the importance of taking into account experimental dependencies in the simulation and real data studies.
Bioinformatics 01/2012; 28(6):815-22. · 5.47 Impact Factor
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ABSTRACT: To facilitate cloning gene(s) underlying gpa7, a deep-coverage BAC library was constructed for an isolate of common wild rice (Oryza rufipogon Griff.) collected from Dongxiang, Jiangxi Province, China (DXCWR). gpa7, a quantitative trait locus corresponding to grain number per panicle, is positioned in the short arm of chromosome 7. The BAC library containing 96,768 clones represents approximate 18 haploid genome equivalents. The contig spanning DXCWR gpa7 was constructed with a series of ordered markers. The putative physical map near the gpa7 locus of another accession of O. rufipogon (Accession: IRGC 105491) was also isolated in silico. Analysis of the physical maps of gpa7 indicated that a segment of about 150 kb was deleted during domestication of common wild rice.
Plant Cell Reports 07/2008; 27(6):1087-92. · 2.27 Impact Factor
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ABSTRACT: As a prerequisite for the map-based cloning of genes from common wild rice (Oryza rufipogon Griff.), which plays an important role in the domestication of cultivated rice (O. sativa L.), we constructed a median-insert size bacterial artificial chromosome (BAC) library of the common wild rice isolate, YJCWR, collected from Yuanjiang, Yunnan Province, China. The library consists of 52,992 clones, with an average insert size of 50 kb, and all clones were pooled into 46 three-dimensional super-pools to facilitate library screening through the PCR method. Seventeen candidate clones were isolated by five markers and some clones containing putative target regions were sequenced. Furthermore, in analyzing the sequences of YJCWR, a retrotransposon, SZ-55, that might contribute to the evolution of Oryza was found.
Biotechnology Letters 04/2008; 30(3):555-61. · 1.68 Impact Factor
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Jun Yu,
Jun Wang,
Wei Lin,
Songgang Li,
Heng Li,
Jun Zhou,
Peixiang Ni,
Wei Dong,
Songnian Hu,
Changqing Zeng, [......],
Bailin Hao,
Siqi Liu,
Wen Wang,
Longping Yuan,
Mengliang Cao,
Jason McDermott,
Ram Samudrala,
Jian Wang,
Gane Ka-Shu Wong,
Huanming Yang
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ABSTRACT: We report improved whole-genome shotgun sequences for the genomes of indica and japonica rice, both with multimegabase contiguity, or almost 1,000-fold improvement over the drafts of 2002. Tested against a nonredundant collection of 19,079 full-length cDNAs, 97.7% of the genes are aligned, without fragmentation, to the mapped super-scaffolds of one or the other genome. We introduce a gene identification procedure for plants that does not rely on similarity to known genes to remove erroneous predictions resulting from transposable elements. Using the available EST data to adjust for residual errors in the predictions, the estimated gene count is at least 38,000-40,000. Only 2%-3% of the genes are unique to any one subspecies, comparable to the amount of sequence that might still be missing. Despite this lack of variation in gene content, there is enormous variation in the intergenic regions. At least a quarter of the two sequences could not be aligned, and where they could be aligned, single nucleotide polymorphism (SNP) rates varied from as little as 3.0 SNP/kb in the coding regions to 27.6 SNP/kb in the transposable elements. A more inclusive new approach for analyzing duplication history is introduced here. It reveals an ancient whole-genome duplication, a recent segmental duplication on Chromosomes 11 and 12, and massive ongoing individual gene duplications. We find 18 distinct pairs of duplicated segments that cover 65.7% of the genome; 17 of these pairs date back to a common time before the divergence of the grasses. More important, ongoing individual gene duplications provide a never-ending source of raw material for gene genesis and are major contributors to the differences between members of the grass family.
PLoS Biology 03/2005; 3(2):e38. · 11.45 Impact Factor
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Qingyou Xia,
Zeyang Zhou,
Cheng Lu,
Daojun Cheng,
Fangyin Dai,
Bin Li,
Ping Zhao,
Xingfu Zha,
Tingcai Cheng,
Chunli Chai, [......],
Jianguo Zhang,
Yong Zhang,
Hongkun Zheng,
Bingyu Mao,
Wen Wang,
Chen Ye,
Songgang Li,
Jian Wang,
Gane Ka-Shu Wong,
Huanming Yang
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ABSTRACT: We report a draft sequence for the genome of the domesticated silkworm (Bombyx mori), covering 90.9% of all known silkworm genes. Our estimated gene count is 18,510, which exceeds the 13,379 genes reported for Drosophila melanogaster. Comparative analyses to fruitfly, mosquito, spider, and butterfly reveal both similarities and differences in gene content.
Science 01/2005; 306(5703):1937-40. · 31.20 Impact Factor
