Oxidative-damage effect of Fe3O4 nanoparticles on mouse hepatic and brain cells in vivo

To assess the biological safety of Fe3O4 nanoparticles （NPs）, the oxidative-damage effect of these NPs was studied. Twenty-five Kunming mice were exposed to Fe3O4 NPs by intraperitoneai injection daily for 1 week at doses of 0, 10, 20, and 40 mg.kg1. Five Kunming mice were also injected with 40 mg.kg 1 ordinary Fe3O4 particles under the same physiological conditions. Biomarkers of reactive oxygen species （ROS）, glutathione （GSH）, and malondialdehyde （MDA） in the hepatic and brain tissues were detected. Results showed that no significant difference in oxidative damage existed at concentrations lower than 10 mg.kg i for NPs compared with the control group. Fe3O4 NP concentration had obvious dose-effect relationships （P〈 0.05 or P 〈 0.01） with ROS level, GSH content, and MDA content in mouse hepatic and brain tissues at〉20 mg.kg 1 concentrations. To some extent, ordinary Fe3O4 particles with 40mg.kg -1 concentration also affected hepatic and brain tissues in mice. The biological effect was similar to Fe3O4 NPs at 10 mg. kg-1 concentration. Thus, Fe3O4 NPs had significant damage effects on the antioxidant defense system in the hepatic and brain tissues of mice, whereas ordinary Fe3O4 had less influence than Fe3O4 NPs at the same concentration.     

Prophylactic effect of vitamin E against hepatotoxicity,nephrotoxicity, haematological indices and histopathology induced by diazinon insecticide in mice

Considering that the involvement of reactive oxygen species （ROS） has been implicated in the toxicity of various pesticides, this study was designed to study the ameliorative effect of Vitamin E （100 mg/kg body weight） on mice （25 -30 mg） treated with diazinon （32.5 or 16.25 mg/kg body weight） organophosphate insecticide for 14 days. Subehronic DZN exposure and the protective effects of vitamins E （vitE） were evaluated for their effects on haematological indices, the enzymes concerning liver damage [plasma alanine aminotransferase （ ALT）, aspartate aminotaransferase （ AST）, alkaline phosphatise （ ALP）, and some parameters of kidney function （urea and creatinine） in mice. Additionally, the histopathological changes in liver and kidney tissue were examined. The high dose of diazinon （DZNH） decreased the body weight significantly at the end of experiment. Additionally, the liver and kidney were examines for histopathological changes. The high dose of diazinon decreased body weight significandy. Moreover, there was a statistically significant decrease in haemoglobin （Hb）, red blood cell （RBC） and hematocrit （Hct） in diazinon-treated mice compared to controls. This decrease was partially remedied in the diazinon-treated group that also received vitE. Damage in the liver and kidney tissues was also evident as elevated plasma ALT, AST, ALP, urea and creatinine. VitE partially counteracts the toxic effect of DZN and repairs tissue damage in the liver and kidney, especially when supplemented to 1/4 LD50 intoxicated animals. Histopathological changes in liver and kidney were observed only in 32.5 mg/kg DZN given group. These results suggest that the effects of DZN are dose dependent. No pathological findings were observed in vitE ＋ DZNtreated groups. According to the present study, we conclude that vitE ean reduce the detrimental impacts of diazinon on haematological indicies, as well as liver and kidney function [ Current Zoology 55 （3） ： 219 - 226, 2009].     

Molecular dynamics reveal a novel kinase-substrate interface that regulates protein translation

A key control point in gene expression is the initiation of protein translation, with a universal stress response being constituted by in- hibitory phosphoryiation of the eukaryotic initiation factor 2α （el F2oL）. In humans, four kinases sense diverse physiological stresses to regulate elF2α to control cell differentiation, adaptation, and survival. Here we develop a computational molecular model of elF2α and one of its kinases, the protein kinase R, to simulate the dynamics of their interaction. Predictions generated by coarse-grained dynamics simulations suggest a novel mode of action. Experimentation substantiates these predictions, identifying a previously unrecognized interface in the protein complex, which is constituted by dynamic residues in both elF2α and its kinases that are crucial to regulate protein translation. These findings call for a reinterpretation of the current mechanism of action of the el F2α kinases and demonstrate the value of conducting computational analysis to evaluate protein function.     

Identification and characterization of genes involved in the jasmonate biosynthetic and signaling pathways in mulberry （Morus notabilis）

Jasmonate （JA） is an important phytohormone regulating growth, development, and environmental response in plants, particularly defense response against herbivorous insects. Recently, completion of the draft genome of the mulberry （Morus notabilis） in conjunction with genome sequencing of silkworm （Bombyx mori） provides an opportuni-ty to study this unique plant-herbivore interaction. Here, we identified genes involved in JA biosynthetic and signaling pathways in the genome of mulberry for the first time, with the majority of samples showing a tissue-biased expression pattern. The analysis of the representative genes 12-oxophy-todienoic acid reductase （OPRs） and jasmonate ZIM-domain （JAZs） was performed and the results indicated that the mulberry genome contains a relatively smal number of JA biosynthetic and signaling pathway genes. A gene encoding an＆amp;nbsp;important repressor, MnNINJA, was identified as an alternative splicing variant lacking an ethylene-responsive element binding factor-associated amphiphilic repression motif. Having this fundamental information wil facilitate future functional study of JA-related genes pertaining to mulberry-silkworm interactions.     

The anorexic effect of Ex4/Fc through GLP-1 receptor activation in high-fat diet fed mice

Exendin-4 （Ex4）, a peptide initially found in the saliva of the Gila monster, can activate the signaling pathway of the incre- tin hormone glucagon-like peptide-1 （GLP-1） through the GLP-1 receptor （GLP-1R）. We previously reported that a chimera protein consisting of Ex4 and mouse IgG heavy chain constant regions （Ex4/Fc） can exert biological effects of GLP-1, such as improving glycemic control and ameliorating manifestations in diabetic mice. The aim of this study was to determine whether Ex4/Fc is effective in modulating energy homeostasis in mice. Our results showed that in vivo expres- sion of Ex4/Fc by intramuscular injection of the plasmid en- coding Ex4/Fc followed by local electroporation effectively decreased food intake in the mice on high-fat diet （HFD） feeding. In addition, the reduced energy intake was associated with the decreased excrements from the Ex4/Fc-treated HFD mice but not the Fc control mice. Remarkably, the Ex4/Fc- treated HFD mice displayed significantly lower triglyceride （TG） levels when compared with the control mice. Interest- ingly, while the leptin levels were not changed, the circulating ghrelin levels were higher in Ex4/Fc mice than those in the Fc control mice. These results suggested that Ex4/Fc can improve energy metabolism and lipid metabolism through GLP-1R in mice under excessive nutrition conditions.     

Role of chaperone-mediated autophagy in degrading Huntington＇s disease-associated huntingtin protein

Mutant N-terminal huntingtin （Htt） protein resulting from Huntington＇s disease （HD） with expanded polyglutamine accumulates and forms aggregates in vulnerable neurons. Both ubiquitin proteasomai and autophagic pathways con- tribute to the degradation of mutant Htt. Here, we focus on the involvement of chaperone-mediated autophagy （CMA）, a selective form of autophagy in the clearance of Htt. Selective catabolism in CMA is conferred by the presence of a KFERQ-Iike targeting motif in the substrates, by which molecular chaperones recognize the hydrophobic surfaces of the misfolded substrates, and transfer them to the lysosomal membrane protein type-2A, LAMP-2A. The substrates are taken into the lysosomes through LAMP-2A and are rapidly degraded by the lysosomal enzymes. Taken together, we summarize the recent evidence to elucidate that Htt is also a potential substrate of CMA. We propose that the manipulation of CMA could be a therapeutic strat- egy for HD.     

失血性休克大鼠淋巴管及血管压力对去甲肾上腺素反应的相关性研究

目的:观察失血性休克(HS)大鼠淋巴管与血管对去甲肾上腺素(NE)反应性的变化,探讨淋巴管与血管反应性的关系。方法:大鼠行左侧腹部手术,分离胸导管,测量淋巴管压力(LP);股部手术,经股动脉测量平均动脉血压(MAP)。休克组经股动脉放血复制HS模型(维持MAP40mmHg左右,3h),假手术(sham)组仅手术。在休克不同时间点(或相当),股静脉注射NE(5μg/kg.bw),观察给予NE前后两组大鼠LP以及MAP的变化。结果:休克即刻淋巴管对NE的反应性与sham组无明显差异,到休克0.5h时淋巴管对NE的升压反应开始减弱,至休克3h依然维持低反应性;与sham组相比,休克组血管对NE反应性呈双相表现,休克即刻血管高反应性,休克1h后对NE的升压作用开始减弱,表现为血管低反应性;休克后二者的反应性相关。结论:大鼠HS后淋巴管出现低反应性,且出现在血管低反应性之前;休克发展进程中淋巴管与血管对NE的低反应性呈正相关。     

下坡跑后大鼠腓肠肌成肌调节因子的变化

目的:探讨成肌调节因子(MyoD)在肌肉损伤修复过程中的动态表达,为促进运动肌肉损伤的再生修复提供实验依据。方法:将健康雄性2月龄SD大鼠80只,随机分为对照组(n=10)和下坡运动组(n=70),下坡运动组再分为运动后即刻组、12h、24h、48h、72h、7d和14d组,各运动组动物均进行持续性下坡跑,分别在运动结束后8个时间点麻醉,下腔静脉取血,分离血清,取双侧腓肠肌。常规检测CK、LDH的活性。采用免疫组织化学染色法以及计算机图像分析技术定量统计MyoD因子表达情况。结果:血清CK、LDH在运动后即刻显著上升,后逐渐下降至正常水平。成肌调节因子MyoD在正常骨骼肌中即有表达,各运动组大鼠腓肠肌MyoD因子表达较对照组均有增加,48h组大鼠腓肠肌MyoD免疫阳性细胞核数明显多于对照组(P0.05),后随时间逐渐下降。结论:离心运动后即刻MyoD的表达水平开始上升,48h达到峰值,随后逐渐下降至正常水平。提示成年早期大鼠(2月龄)已具备较成熟的肌肉再生修复能力。     

An active piggyBac-like element in Macdunnoughia crassisigna

In this paper, a highly conservedpiggyBac-like sequence, designated as McrPLE was cloned from a lepidopteran insect, Macdunnoughia crassisigna. It is 2 472 bp long in full length with a single open reading frame and encodes a 595 amino acid transposase. It shares identical terminal and sub-terminal repeats with T. ni IFP2 and is flanked by the typical TTAA target-site duplications. Alignment and phylogenetic analysis revealed that McrPLE had greater than 99.5% identity and appeared to be the closest one in phylogeny to IFP2 among the PLEs so far found in various species. Plasmid-based excision and transposition assay proved it was mobile in cell culture. Otherwise, McrPLE element and all other highly conserved IFP2 sequences reported previously were found to share three common nucleotide substitutions. This suggests that the original IFP2 may be a related variant of a predecessor element that became widespread. The existence of nearly identical piggyBac sequence in reproductively isolated species was thought also a strong indication of horizontal transmission, which raises important considerations for the stability and practical use ofpiggyBac transformation vectors.     

Intracellular and Extracellular Phosphatidylinositol 3-Phosphate Produced by Phytophthora Species Is Important for Infection

RxLR effectors produced by Phytophthora pathogens have been proposed to bind to phosphatidylinositol 3-phosphate （Ptdlns（3）P） to mediate their translocation into host cells and/or to increase their stability in planta. Since the levels of Ptdlns（3）P in plants are low, we examined whether Phytophthora species may produce Ptdlns（3）P to pro- mote infection. We observed that Ptdlns（3）P-specific GFP biosensors could bind to P. parasitica and P. sojae hyphae dur- ing infection of Nicotiana benthamiana leaves transiently secreting the biosensors, suggesting that the hyphae exposed Ptdlns（3）P on their plasma membrane and/or secreted Ptdlns（3）R Silencing of the phosphatidylinositol 3-kinases （PI3K） genes, treatment with LY294002, or expression of Ptdlns（3）pobinding proteins by P. sojae reduced the virulence of the pathogen on soybean, indicating that pathogen-synthesized Ptdlns（3）P was required for full virulence. Secretion of Ptdlns（3）P-binding proteins or of a PI3P-5-kinase by N. benthamiana leaves significantly increased the level of resist- ance to infection by P. parasitica and P. capsici. Together, our results support the hypothesis that Phytophthora species produce external Ptdlns（3）P to aid in infection, such as to promote entry of RxLR effectors into host cells. Our results derived from P. sojae RxLR effector Avrlb confirm that both the N-terminus and the C-terminus of this effector can bind Ptdlns（3）P.     

Expression of acid-sensing ion channels in nucleus pulposus cells of the human intervertebral disk is regulated by non-steroid anti-inflammatory drugs

Non-steroid anti-inflammatory drugs （NSAIDs） are general- ly used in the treatment of inflammation and pain through cyclooxygenase （COX） inhibition. Mounting evidence has indicated additional COX-independent targets for NSAIDs including acid-sensing ion channels （ASICs） la and 3. However, detailed function and mechanism of ASICs still remain largely elusive. In this study, the impact of NSAIDs on ASICs in nucleus puiposus cells of the human interverte- bral disk was investigated. Nucleus pulposus cells were iso- lated and cultured from protruded disk tissues of 40 patients. It was shown that ASICla and ASIC3 were expressed and functional in these cells by analyzing proton- gated currents after ASIC inhibition. We further investi- gated the neuroprotective capacity of ibuprofen （a COX in- hibitor）, psaimotoxin-1 （PcTX1, a tarantula toxin specific for homomeric ASICla）, and amiloride （a classic inhibitor of the epithelial sodium channel ENaC/DEG family to which ASICs belong）. PcTXl-containing venom has been shown to be comparable with amiloride in its neuroprotective features in rodent models of ischemia. Taken together, our data showed that amiloride, PcTX1, and ibuprofen decreased ASIC protein expression and thereby exerted protective effects from ASIC inhibition-mediated cell damage.     

Efficient production of transgenic chickens using self-inactive HIV- based lentiviral vectors

We demonstrated the simple and effective production of transgenic chickens, in which the enhanced green fluorescence protein （EGFP） was expressed by using third-generation self-inactive HIV-based lentiviral vectors. In our experiments, lentiviruses were injected into 204 fertilized eggs, from which 30 （15%） chickens were hatched. The exogenous gene was detected in the genomes of 16 out of 30 （53%） chickens. The green fluorescence signal was observed directly in various body parts, and was particularly significant in the testes. The transgenes were also found in the offspring of these chickens. The results indicate that HIV-based lentiviral vectors can be used to generate transgenic birds economically and effectively [ Current Zoology 55 （5）： 383 - 387,2009].     

Role of BDNF in the taste system

Neurotrophins are a family of proteins that regulate neural survival, development, function and plasticity in the central and the peripheral nervous system. There are four neurotrophins： NGF, BDNF, NT-3 and NT-4. Among them, BDNF is mostly studied in the taste system due to its high expression. Recent studies have shown BDNF play an important role in the developmental and mature taste system, by regulating survival of taste cells and geniculate ganglion neurons, and maintaining and guiding taste nerve innervations. These studies imply BDNF has great potentialities for therapeutic usage to enhance sensory regeneration following nerve injury, with aging, and in some neurodegenerative diseases.     

HIV-1 Vpr-induced cell death in Schizosaccharomyces pombe is reminiscent of apoptosis

Human immunodeficiency virus type 1 （HIV-1） Vpr induces cell death in mammalian and fssion yeast cells, suggesting that Vpr may affect a conserved cellular process. It is unclear, however, whether Vpr-induced yeast cell death mimics Vpr-mediated apoptosis in mammalian cells. We have recently identified a number of Vpr suppressors that not only suppress Vpr-induced cell death in fission yeast, but also block Vpr-induced apoptosis in mammalian cells. These findings suggest that Vpr-induced cell death in yeast may resemble some of the apoptotic processes of mammalian cells. The goal of this study was to develop and validate a fission yeast model system for future studies of apoptosis. Similar to Vpr-induced apoptosis in mammalian cells, we show here that Vpr in fission yeast promotes phosphatidylserine externalization and induces hyperpolarization of mitochondria, leading to changes of mitochondrial membrane potential. Moreover, Vpr triggers production of reactive oxygen species （ROS）, indicating that the apoptotic-like cell death might be mediated by ROS. Interestingly, Vpr induces unique morphologic changes in mitochondria that may provide a simple marker for measuring the apoptotic-like process in fission yeast. To verify this possibility, we tested two Vpr suppressors （EF2 and Hspl6） that suppress Vpr-induced apoptosis in mammalian cells in addition to a newly identified Vpr suppressor （Skpl）. All three proteins abolished cell death mediated by Vpr and restored normal mitochondrial morphology in the yeast cells. In conclusion, Vpr-induced cell death in fission yeast resembles the mammalian apoptotic process. Fission yeast may thus potentially be used as a simple model organism for the future study of the apoptotic-like process induced by Vpr and other proapoptotic agents.     

ifirmed Diagnosis by RT-PCR and Phylogenetic Analysis of Peste des Petits Ruminants Viruses in Tibet,China

This paper reports the confirmed diagnosis by nested RT-PCR of PPR cases in Tibet, China in 2007, and results of phylogenetic analysis. Results showed that the 11 tested samples were PPRV positive by nested RT-PCR, of which 2 samples were genetically close to the X7443 strain （Nigeria 75/1） of lineage I, and 3 samples close to the strain AY560591 （Sungri96） of linage IV with 96.6%, 97.3%, 97.6% and 98% nucleotide sequence homogeneity respectively, based on partial sequencing of the F gene from 5 samples and complete sequencing of the N/M/F/H genes from one sample. This study suggested that there are at least 2 origins of PPRV in China.     

Systematic positions of Lamiophlomis and Paraphlomis （Lamiaceae） based on nuclear and chloroplast sequences

Genera Lamiophlomis and Paraphlomis were originally separated from genus Phlomis s.1. on the basis of particular morphological characteristics. However, their relationship was highly contentious, as evidenced by the literature. In the present paper, the systematic positions of Lamiophlomis, Paraphlomis, and their related genera were assessed based on nuclear internal transcribed spacer （ITS） and chloroplast rpl16 and trnL-F sequence data using maximum parsimony （MP） and Bayesian methods. and outgroup were sampled. Analyses of both separate In total, 24 species representing six genera of the ingroup and combined sequence data were conducted to resolve the systematic relationships of these genera. The results reveal that Lamiophlomis is nested within Phlomis sect. Phlomoides and its generic status is not supported. With the inclusion ofLamiophlomis rotata in sect. Phlomoides, sections Phlomis and Phlomoides of Phlomis were resolved as monophyletic. Paraphlomis was supported as an independent genus. However, the resolution of its monophyly conflicted between MP and Bayesian analyses, suggesting the need for expended sampling and further evidence.