A new phenolic glycoside from the aerial parts of Solidago canadensis

A new phenolic glycoside, 2'-hydroxy-4',6'-di-O-beta-D-glucopyranosyl-butyrrophenone (1), was isolated from the aerial parts of Solidago canadensis. The structure was elucidated on the basis of spectroscopic methods.     

A new flavonoid glycoside from the leaf of Cephalotaxus koreana

A new flavone glycoside, apigenin 5-O-alpha-L-rhamnopyranosyl-(1-->3)-beta-D-glucopyranoside (1), along with four known flavonol glycosides (2-5), were isolated from the leaf of Cephalotaxus koreana. The new glycoside 1 showed inhibitory activity in superoxide radical scavenging assay with IC(50) value of 13.0 microM, while it showed weak activity in 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay. Compounds 2-5 exhibited antioxidant activity in scavenging DPPH and superoxide radicals with IC(50) values ranging from 5.7 to 22.3 microM.     

苯并噻二唑诱发水稻对稻瘟病抗性中防卫相关酶活性的变化

分析了苯并噻二唑（BTH）诱导水稻对稻瘟病抗性中苯丙氨酸解氨酶（PAL）、肉桂醇脱氢酶（CAD）、过氧化物酶（POD）、脂氧合酶（LOX）、β-1,3-葡聚糖酶和几丁酶等活性的变化。结果表明BTH诱导处理亲和性水稻品种第3叶后提高了处理叶及其上位第4叶中CAD、LOX和β-1,3-葡聚糖酶等的活性;经BTH处理的幼苗接种稻瘟菌后,处理叶和其上位叶中CAD、POD、LOX和β-1,3-葡聚糖酶等活性快速增加,且增长幅度均显著大于对照。几丁酶活性在受稻瘟菌侵染后升高,但BTH诱导处理并不能促进其增加;PAL活性在BTH处理及稻瘟菌接种后均无明显变化。这些结果说明,BTH处理能诱导CAD、POD、LOX和β-1,3-葡聚糖酶等活性的增加,而且这些酶活性的升高可能与BTH诱发系统获得抗性的表现有关。     

尖孢镰刀菌β-D-葡萄糖苷酶异质性的研究

对黄瓜和瓠瓜不同部位以及不同寄主上分离的尖孢镰刀菌β-D-葡萄糖苷酶活性进行了测定,结果表明,4株瓠瓜不同部位分离的尖孢镰刀菌β-D-葡萄糖苷酶活性差异不大,分别为21.8233 U、22.1663 U、21.4573 U和17.587 U。黄瓜不同部位分离的尖孢镰刀菌的β-D-葡萄糖苷酶活性差异较大,分别为23.907 U、22.0983 U、35.736 U和34.5323 U。不同寄主尖孢镰刀菌的β-D-葡萄糖苷酶活性变化范围为10.21830 U~39.82230 U,其变化依次为：西瓜＞黄瓜＞瓠瓜＞甜瓜＞豇豆＞辣椒。     

投喂雌二醇对西伯利亚鲟幼鱼生长及血液生化指标的影响

采用投喂添加雌二醇饲料的试验方法,观察分析人工诱导西伯利亚鲟性逆转过程中,外源雌激素对西伯利亚鲟幼鱼生长和血液生化指标的影响。研究结果表明:高剂量组(10 mg E2/kg饲料)幼鱼的日增重、肥满度、特定生长率等均显著低于低剂量组(1 mg E2/kg饲料)、对照组和空白组(P0.05),且高剂量组血清中血糖和总胆固醇显著降低(P0.05),而总磷含量显著升高(P0.05)。     

聚β-羟基丁酸酯对中国明对虾(Fenneropenaeus chinensis)非特异性免疫相关酶的影响

本研究以中国明对虾(Fenneropenaeus chinensis)为对象,探讨不同浓度的聚β-羟基丁酸酯(Poly-β-hydroxybutyrate,PHB)对其非特异性免疫相关酶的影响.实验采用单因子浓度梯度法,对健康的中国明对虾投喂添加不同浓度PHB(0、0.5％、1.0％、2.5％、5.0％、10.0％)的饲料,分别对应对照组C和实验组E0.5、E1.0、E2.5、E5.0、E10.0组,饲喂6周,统计每组中国明对虾的死亡率和相对免疫保护率,检测总抗氧化能力(T-AOC)、酸性磷酸酶(ACP)、过氧化物酶(POD)和过氧化氢酶(CAT)、超氧化物歧化酶(SOD)5种酶的活力及丙二醛(MDA)含量与时间、PHB浓度的变化关系.结果显示,实验组的相对免疫保护率随PHB浓度的增加呈现先上升后下降的趋势.E1.0组为最高值,并且与其他各组相比差异显著(P＜0.05).随PHB浓度的增加,免疫酶活力整体变化趋势为先上升后下降.在时间分布上,饲喂2-3周时,酶活力呈现高水平表达,其中,T-AOC在血清(E1.0、E2.5组)、肝胰腺(E1.0组);ACP在血清(E1.0、E2.5组)、肝胰腺(E1.0组);CAT在血清(E0.5、E1.0、E2.5组)、肝胰腺(E0.5、E1.0、E10.0组);POD在血清和肝胰腺(E0.5、E1.0、E2.5组);SOD在血清和肝胰腺(E1.0组)以及MDA在血清(E1.0组)、肝胰腺(E0.5,E1.0组)较其他组均具有显著性差异(P＜0.05).研究表明,PHB添加剂对中国明对虾免疫水平的提高具有促进作用.综合各组和各时间段免疫酶的变化,E1.0为最适浓度组,投喂2-3周时其免疫酶总体具有高水平活力值.     

猪宿主蛋白G3BP1对猪圆环病毒2型在PK15细胞上复制的影响

猪宿主蛋白G3BP1在宿主抵抗病毒感染过程中起着重要作用,然而还未有相关报道G3BP1与猪圆环病毒2型(PCV2)感染过程中的联系。本文构建了G3BP1真核表达载体和干扰RNA,实现在PK15细胞上G3BP1的过表达及敲低。结果发现,PCV2感染细胞24 h后病毒复制出现显著差异,感染48 h相比于感染24 h病毒复制差异更显著,表明G3BP1能显著促进PCV2复制。过表达或敲低G3BP1后,用干扰素刺激DNA(ISD)刺激12 h,G3BP1能促进ISD诱导IFN-βmRNA的表达;感染PCV212 h后,G3BP1也能正调控IFN-βmRNA的转录。本文揭示了宿主蛋白G3BP1显著促进PCV2的复制,很可能是通过上调IFN-β表达引起的。     

三明野生蕉β-1,3-葡聚糖酶Mugsp7基因克隆及其在低温处理下的表达分析

以三明野生蕉组培苗为材料,通过RT-PCR技术克隆获得β-1,3-葡聚糖酶基因Mugsp7（β-1,3-glucanase）的 cDNA 和 gDNA 序列,并对该基因进行生物信息学分析和不同低温下的实时荧光定量PCR表达分析,并进一步测定8 ℃处理1、2、3、4和5 d后三明野生蕉叶片β-1,3-葡聚糖酶活性。结果表明：Mugsp7的 gDNA 长 1132 bp,开放阅读框（ORF）长984 bp,具有一个148 bp的内含子,共编码 327 个氨基酸。cDNA、gDNA 的登录号分别为 KU363808和KU363809。生物信息学分析表明,Mugsp7 属于酸性、亲水、稳定性蛋白,不具有信号肽,与小果野蕉、大叶藻、玉米、大麦、水稻等位于同一分支,与小果野蕉亲缘关系较近分为一类。实时荧光定量PCR表明,不同低温处理和8 ℃低温不同时间处理下,Mugsp7 呈现不同表达模式,且三明野生蕉叶片β-1,3-葡聚糖酶活性的测定分析也进一步表明,Mugsp7 能进一步响应低温胁迫。因此,推测 Mugsp7 在三明野生蕉抗寒响应中发挥重要作用。     

调控民猪Tβ4基因转录因子的筛选与分析

为了筛选调控民猪胸腺β4（Tβ4）基因转录的增强子，探究该基因的表达调控机制，本研究以民猪基因组DNA为模板，通过PCR扩增Tβ4基因启动子区系列截短片段，与pMD18-T载体连接构建克隆质粒；通过双酶切和连接反应将系列截短片段定向连入pGL3-basic载体构建双荧光素酶重组质粒；将重组质粒转染PK15细胞系，利用双荧光素酶检测系统测定重组质粒的相对荧光素酶活性；根据相对荧光素酶活性的高低进一步筛选Tβ4基因的启动子核心区域；利用3个在线软件预测核心区域内的转录因子结合位点，根据预测结果，使用重叠PCR定点缺失转录因子结合位点构建突变载体，在PK15细胞中以野生型载体为对照检测突变载体的相对荧光素酶活性。结果表明，试验成功构建了6个Tβ4基因系列截短的启动子片段，其中5个片段具有明显的活性。经过两轮的双荧光素酶活性检测发现，-155~-105 bp区域为民猪Tβ4基因的启动子核心区域，经生物信息学分析发现，该区域存在E2F-1、MYBAS1和ELK-1转录因子的结合位点。利用定点缺失构建了3个转录因子缺失的突变载体，经双荧光素酶检测发现仅有ELK-1结合位点的缺失，会造成启动子活性的显著下降（P<0.05）。据此推测ELK-1是民猪Tβ4基因转录的正调控元件。     

Baicalin attenuates pancreatic fibrosis by inhibiting TGF-β1/TAK-NF-κB signaling pathway in chronic pancreatitis mice

AIM: To explore the role of transforming growth factor-β1 (TGF-β1)/TGF-β-activated kinase (TAK)-nuclear factor-κB (NF-κB) signaling pathway in chronic pancreatitis (CP) mice and the effect of baicalin on pancreatic fibrosis in the mice. METHODS: Kunming mice (n=58) were randomly divided into 3 groups, including control group, CP group and baicalin group. The mice in CP group and baicalin group were intraperitoneally injected with 20% L-arginine. After 2 weeks of CP, the mice in baicalin group were intraperitoneally injected with baicalin (100 mg/kg, once a day). At 2 weeks, 4 weeks and 6 weeks after modeling, the mice were anesthetized and sacrificed. The morphological changes of the pancreas were observed by HE and Masson staining. The serum level of TGF-β1 was analyzed by ELISA. The expression of fibronectin (FN) and NF-κB in the pancreas was observed by immunohistochemistry staining. The protein levels of transforming growth factor-β receptor type Ⅰ (TGF-βRⅠ), phosphorylated TAK1 (p-TAK1) and NF-κB in the pancreas were determined by Western blot. The mRNA expression of matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloprotease-1 (TIMP-1) was detected by real-time PCR. RESULTS: At 2 weeks, 4 weeks and 6 weeks after intraperitoneal injection of L-arginine, the pancreatic tissues were obviously injured and exhibited different degrees of fibrosis, and FN expression was significantly increased. After treatment with baicalin, the degrees of pancreatic injury and fibrosis were significantly attenuated and the expression of FN was reduced (P<0.01). Compared with control group, the protein levels of TGF-β1, TGF-βRⅠ, p-TAK1, NF-κB and TIMP-1 in the pancreas of CP group were significantly increased, and the expression of MMP-1 was decreased at each time point. In baicalin group, the protein levels of TGF-β1, TGF-βRⅠ, p-TAK1, NF-κB and TIMP-1 were significantly decreased, and the expression of MMP-1 was markedly increased at the corresponding time points compared with CP group (P<0.01). CONCLUSION: Baicalin effectively atte-nuates pancreatic fibrosis by inhibiting the activation of TGF-β1/TAK-NF-κB signaling pathway and regulating the balance of MMP-1/TIMP-1.