枸杞多糖-4a改善糖尿病大鼠胰岛素抵抗作用的研究

试验旨在研究枸杞多糖亚级分（LBP-4a）改善非胰岛素依赖型糖尿病(NIDDM)大鼠胰岛素抵抗（IR）的作用及其机制。试验采用水提醇沉法从宁夏枸杞中提取出枸杞多糖,并对其进行分离、纯化得主要活性成分LBP-4a。采用高糖高脂饮食结合小剂量腹腔注射链脲佐菌素(STZ)建立NIDDM大鼠模型,并将其分为模型对照组、LBP-4a低、高剂量组和罗格列酮治疗组,同时设立正常对照组。给药8周后检测相关指标。采用单细胞凝胶电泳技术对LBP-4a降糖、改善IR的作用机理进行了较为深入系统的探讨。结果表明,LBP-4a不仅对NIDDM大鼠具有降脂和增加抗氧化性的功能,还具有修复DNA损伤的作用。因此,LBP-4a作为一种可食的添加物能改善NIDDM大鼠的IR,进而预防NIDDM并发症及癌变的发生。     

茶树莽草酸代谢途径相关基因研究进展

莽草酸生物合成是连接植物初生代谢和次生代谢的关键节点。目前,莽草酸合成代谢途径关键基因的克隆、功能验证及表达调控的研究取得了一定成果,对调控茶树生长发育、提高茶叶产量和品质等研究均有重要意义。为此,本综述就莽草酸代谢途径与茶叶产量品质形成的相关性、相关调控基因研究进展,以及其他植物中该途径相关基因研究进展等进行了总结,以期为茶树遗传育种基础理论及高效育种技术的研发等提供参考。     

β-罗勒烯信号传导途径关键基因突变体的筛选

罗勒烯作为一种植物通讯信号分子可以诱导植物的整体防御反应,但是目前对β-罗勒烯信号传导途径上的关键组分并不清楚。为了找到β-罗勒烯信号传导途径关键基因的突变体,本研究采用正向遗传学的方法,以带有PDF1.2pro::Luciferase和PR1pro::Luciferase表达框的转基因拟南芥为背景材料(M0),选用0.2%(v/v)EMS浓度构建了诱变群体,通过荧光素酶-荧光素活体荧光成像系统检测荧光表型来筛选突变体,成功筛选出了经β-罗勒烯诱导不发荧光的PDF1.2pro::Luciferase突变体植株(Ef)12株和PR1pro::Luciferase突变体植株(E1)10株,并在M2代确定了稳定不发荧光的表型。M3代检测β-罗勒烯信号途径下游基因PDF1.2与PR1的表达,以及测序验证突变体植株PDF1.2pro::Luciferase和PR1pro::Luciferase表达框的完整性,最后确认获得了与β-罗勒烯信号传导途径相关的可靠突变体的Ef材料为8株,E1材料为3株,为进一步探明β-罗勒烯信号传导途径的关键组分及其机制提供依据。     

家蚕先天性免疫的研究进展

蚕桑生产是我国的传统优势产业,但蚕病却给养蚕业造成很大的损失。由于产业发展的需要,家蚕的免疫防御机制是人们长期关注的热点。家蚕虽然不具有人类高度专一的获得性免疫,但具有对病原微生物感染作出快速有效应答的先天性免疫系统。家蚕受到微生物的感染后,体内会合成抗菌肽,然后抗菌肽被分泌到血淋巴中去消灭病原体。其中,模式识别受体、免疫信号传导途径以及抗菌肽在体液免疫中起着非常重要的作用。     

盐胁迫下交替呼吸对二斑叶螨侵染叶片及其间接防御的影响

为探索在遭受盐胁迫时二斑叶螨Tetranychus urticae Koch侵染叶片的交替呼吸途径的生理学功能,在实验室条件下研究了NaCl以及水杨基氧肟酸对二斑叶螨侵染叶片的间接防御反应,以及对过氧化氢含量和细胞死亡水平的影响。200 mmol/L NaCl胁迫没有明显影响二斑叶螨侵染叶片对智利小植绥螨Phytoseiulus persimilis的吸引作用,也没有提高二斑叶螨侵染叶片中过氧化氢含量和细胞死亡的水平,但显著提高了侵染叶片中交替呼吸途径的水平。200 mmol/L NaCl和1mmol/L水杨基氧肟酸的复合处理则显著降低了二斑叶螨侵染叶片对捕食螨的吸引作用,并提高了过氧化氢含量和细胞死亡的水平。研究表明,当二斑叶螨侵染叶片遭受盐胁迫时,交替呼吸途径不仅有助于维持植物的间接防御反应,而且缓解了植物体内的氧化压力和细胞死亡。     

社区文化发展路径研究——以山东省临沂农村为例

随着我国城镇化建设的不断推进,农民对文化的需求不断增长,农村文化建设的重要性日益凸显.重塑农村社会的本土特色文化,引进和吸收城市文化,实现城乡文化资源共享,同时发挥政府引导和村民主体参与作用.在内外力共同推动下,形成农村文化在发展方式、运行机制、服务模式上的文化建设新格局.     

普通小球藻对NH4＋- N、NO2-- N去除效果及NO2-- N消失途径的初步研究

在水产养殖中，氨氮（NH4＋- N）和亚硝酸盐氮（NO2-- N）是危害水产动物生长发育的关键因子。为评估小球藻在调控水体NH4＋- N和NO2-- N的应用前景，本研究以普通小球藻为研究对象，首先确定了小球藻去除水体中NH4＋- N和NO2-- N的适宜条件，其次探究了小球藻作用下水体中NH4＋- N和NO2-- N的变化规律，最后解析了小球藻去除水体NO2-- N的途径。结果显示：在适宜的光照条件下，小球藻具有极佳的氮盐去除效果，在18000 Lux时对NH4＋- N去除率最高（96.23 %），在9000 Lux时对NO2-- N去除率最高（99.19 %）；小球藻去除氮盐顺序为NH4＋- N＞NO3-- N＞NO2-- N；初始藻密度在2.5×105 cells/mL时对NH4＋- N、NO2-- N去除率最高，分别为94.92 %、99.05 %。NH4＋- N下降阶段小球藻亚硝酸盐还原酶活性显著低于NO2-- N下降阶段，表明该还原酶对小球藻去除NO2-- N的关键作用。综上，普通小球藻能显著降低水体NH4＋- N与NO2-- N含量，NO2-- N由藻细胞内亚硝酸盐还原酶还原成NH4＋- N进而被同化吸收。     

Expression of histone chaperone ASF1B in prostate cancer cells and its effect on cell viability in vitro

AIM To investigate the expression of histone chaperone anti-silencing function 1B （ASF1B） in prostate cancer cells and its effect on cell viability in vitro. METHODS Human prostate cancer PC-3 cells were used， and knockdown of ASF1B was conducted by small interfering RNA （siRNA） transfection into the cells. The cells were divided into control group， siRNA negative control vector （mock） group and siRNA-ASF1B group. The viability of the PC-3 cells treated with ASF1B-siRNA for 12， 24 and 48 h was measured by MTT assay. Flow cytometry was used to analyze cell apoptosis and cell cycle distribution. The mRNA expression of apoptosis-related molecules was detected by RT-qPCR， and the expression levels of MAPK/JNK/ERK signaling pathway-related proteins were determined by Western blot. RESULTS The protein level of ASF1B in the normal cells （benign prostatic hyperplasia） was significantly lower than that in the PC-3 cells （P<0.01）. Compared with control group and mock group， the protein expression level of ASF1B in the PC-3 cells transfected with siRNA-ASF1B plasmid and the viability of the PC-3 cells were significantly decreased （P<0.01）. The apoptotic rate of the PC-3 cells transfected with siRNA-ASF1B plasmid was significantly higher than that in control group （P<0.01）， and the cell cycle was arrested at G₁ phase. The mRNA levels of p53， caspase-3， Bax and PARP-1 in the PC-3 cells transfected with siRNA-ASF1B plasmid were up-regulated compared with those in control group and Mack group （P<0.01）. In addition， the protein levels of MAP2K4 and p-JNK in the PC-3 cells in siRNA-ASF1B group were significantly higher than those in mock group （P<0.01）， while the protein level of p-ERK was significantly lower than that in mock group （P<0.01）. CONCLUSION ASF1B silencing induces G₁ arrest and promotes apoptosis of PC-3 cells. Activating MAPK/JNK/ERK signaling pathway may be a possible contributor to the anti-prostate cancer effect of siRNA-ASF1B.     

Cordyceps militaris polysaccharide promotes reverse cholesterol transport in CETP-tg mice

AIM To verify whether Cordyceps militaris polysaccharide （CMPS） has the effect of promoting reverse cholesterol transport （RCT） in vitro and in vivo， and to explore the underlying mechanism. METHODS For in vivo experiments， RCT efficiency was detected in cholesterol ester transporter transgene （CETP-tg） mice by isotope tracer technique， and the plasma lipid levels were measured by enzyme method. For in vitro experiments， the residual lipid content after cholesterol efflux in RAW264.7 macrophage-derived foam cells was tested by oil red O staining and total cholesterol （TC） kit. Western blot was used to analyze the protein expression of the molecules involved in cholesterol transport， uptake and transformation in the foam cells and mice liver. RESULTS After 4 weeks of intragastric administration of CMPS， the concentrations of TC， low-density lipoprotein cholesterol （LDL-C） and high-density lipoprotein cholesterol （HDL-C） in the plasma of CETP-tg mice were reduced by 24%， 23% and 22%， respectively. RCT efficiency of CETP-tg mice was accelerated and the appearance of ³H-cholesterol tracer in plasma， bile， intestine and feces was significantly increased in CMPS group. Meanwhile， the expression levels of cholesterol receptors scavenger receptor B1 （SR-B1） and LDL receptor （LDLR）， and cholesterol converting rate-limiting enzyme cholesterol 7α-hydroxylase A1 （CYP7A1） were upregulated by 105%， 71% and 58% in the liver of CMPS group， respectively. The results of in vitro experiments showed that CMPS preincubation promoted cholesterol efflux， decreased intracellular lipid and TC levels， and up-regulated the expression of peroxisome proliferator-activated receptor γ （PPARγ）-liver X receptor α （LXRα）-ATP-binding cassette transporter A1 （ABCA1）/ABCG1 signaling pathway related proteins in macrophage-derived foam cells. CONCLUSION CMPS promotes excess cholesterol efflux from peripheral macrophage-derived foam cells and accelerates its discharge through liver pathway. PPARγ-LXRα-ABCA1/ABCG1 pathway may be involved in the mechanism.