Effects of macrophage-specific adiponectin expression on lipid metabolism in vivo

Epidemiological studies have associated low circulating levels of the adipokine adiponectin with multiple metabolic disorders, including metabolic syndrome, obesity, insulin resistance, type II diabetes, and cardiovascular disease. Recently, we reported that adiponectin selectively overexpressed in mouse macrophages can improve insulin sensitivity and protect against inflammation and atherosclerosis. To further investigate the role of adiponectin and macrophages on lipid and lipometabolism in vivo, we engineered the expression of adiponectin in mouse macrophages (Ad-TG mice) and examined effects on plasma lipoproteins and on the expression levels of genes involved in lipoprotein metabolism in tissues. Compared with the wild-type (WT) mice, Ad-TG mice exhibited significantly lower levels of plasma total cholesterol (-21%, P < 0.05) due to significantly decreased LDL (-34%, P < 0.05) and VLDL (-32%, P < 0.05) cholesterol concentrations together with a significant increase in HDL cholesterol (+41%, P < 0.05). Further studies investigating potential mechanisms responsible for the change in lipoprotein cholesterol profile revealed that adiponectin-producing macrophages altered expression of key genes in liver tissue, including apoA1, apoB, apoE, the LDL receptor, (P < 0.05), and ATP-binding cassette G1 (P < 0.01). In addition, Ad-TG mice also exhibited higher total and high-molecular-weight adipnection levels in plasma and increased expression of the anti-inflammatory cytokine IL-10 as well as a decrease in the proinflammatory cytokine IL-6 in adipose tissue. These results indicate that macrophages engineered to produce adiponectin can influence in vivo gene expression in adipose tissue in a manner that reduces inflammation and macrophage infiltration and in liver tissue in a manner that alters the circulating lipoprotein profile, resulting in a decrease in VLDL and LDL and an increase in HDL cholesterol. The data support further study addressing the use of genetically manipulated macrophages as a novel therapeutic approach for treatment of cardiometabolic disease.     

杉木与固氮和非固氮树种混交对林地土壤质量和土壤水化学的影响

第 1代人工杉木林皆伐后 ,3种不同的经营模式 ,即连载杉木纯林、杉木与固 N阔叶树混交林和杉木与非固 N阔叶树混交林 ,对林地土壤质量和土壤水化学的影响进行了比较。结果表明 ,在杉树与阔叶树混交经营模式下 ,土壤养分含量增加 ,物理性状改善 ,土壤生物活性提高 ,微生物商 (Cmic:Corg)上升 ,代谢商 (q CO2 )稍有下降 ,但杉木与固 N树种的混交对土壤质量的改善效果比杉木与非固 N树种混交好 ;相反 ,杉木连载只能导致林地土壤质量的逐渐恶化 ;土壤溶液中 ,主要来自于大气中的一些离子浓度 ,如 SO2 - 4,Cl- ,Na 和 Mg2 ,在杉木纯林中显著高于混交林 ,而主要受系统内影响较大的一些离子 ,如 K 和NH 4,NO- 3,在经营模式间变异较小 ;H 和 Al3 浓度也是杉木纯林比混交林高。另外 ,研究结果还表明 ,总有机 C、CEC和微生物 C与其它土壤理化性质与生物学性质之间存在着较好的相关性 ,所以可以将总有机 C、CEC和微生物 C作为红黄壤地区亚热带人工林土壤质量的指示指标     

以职业技能为导向的“动物微生物学”课程高效课堂构建与实践

动物微生物学是高职院校畜牧兽医专业的一门重要基础课,理论性、技术性、实践性很强,其教学效果对学生后续专业的学习、实践技能的掌握有重要影响。本文从课程教学必须适应培养现代专业技术人才的要求出发,探讨了对"动物微生物学"课程教学进行改革与实践的必要性,提出要通过对教学课时的调整、授课内容的优化、教学方式的创新以及多媒体、翻转课堂、理论与实践一体化(以下简称理实一体化)等多种教学手段的综合使用,构建以职业技能为导向的"动物微生物学"课程高效课堂,努力找出一条培养具有相当的专业理论知识、一定的实践操作技能和较高的职业素养的应用型、复合型专业人才的现实途径。     

An Imported Case of Cystic Echinococcosis in the Liver

A 25-year-old Uzbek male presented with right upper abdominal pain for 20 days. On radiologic studies, a huge cystic mass was noticed in the right liver which was suspected as parasitic. The patient received right hepatic segmentectomy (segment 7), and the surgically resected mass was confirmed as cystic echinococcosis (CE), measuring 10.5 cm in its diameter. The inner surface of the cyst was bile-stained. The patient was discharged on the 8th hospital day, and was rechecked 6 months after the surgical intervention without any evidence of recurrence. The present report describes findings of an imported case of CE which represented ultrasound images of the ''ball of wool''.     

广东内伶仃岛猕猴食性及食源植物分析

论文对内伶仃岛猕猴(Macaca mulatta)的植物食性进行了全面调查,并测定了食源植物适食部分的比重。研究结果表明:(1)猕猴食源植物约200种,以叶食性、果食性最为丰富;(2)猕猴的活动区域以阔叶林、灌木林等植被类型为主;(3)食源植物以热带亚热带成分为主,与栖息地植被组成特征相适应;(4)内伶仃岛猕猴种群发展的容纳量最适为820～1640只(平均1230只),而以743～1485只(平均1114只)最为合适,其总食量约相当于适食性优质植物资源总蕴藏量的10%～20%。     

赤霞珠葡萄果实苹果酸生物合成关键转录因子的筛选与鉴定

该研究以宁夏贺兰山东麓酿酒葡萄种植区栽培面积最大的‘赤霞珠’为材料,在前期完成从果实形成至成熟不同发育时期的转录组测序以及关键有机酸含量测定基础上,进一步通过转录因子结合位点预测、差异表达基因分析、加权基因共表达网络关联分析(WGCNA),逐步筛选出与‘赤霞珠’果实苹果酸生物合成相关功能基因特异结合的、影响苹果酸生物合成的相应转录因子,并对其进行qRT PCR验证,以揭示这些关键功能基因及其关键转录因子在葡萄不同种植区、果实不同发育时期存在的相互调控作用机制,为以后培育优质酿酒葡萄提供新的理论依据与思路。结果表明：(1)GC/MS分析发现, ‘赤霞珠’果实在4个发育时期的延胡索酸和苹果酸含量变化趋势基本一致,两种酸含量均从果实硬果期到绿果期逐步升至最高(3.63和626.53 μg/g),之后缓慢下降,经转色期到成熟期后逐渐降至最低(2.14和244.26 μg/g),而草酰乙酸的变化趋势却相反,在硬果期含量最高(315.54 μg/g),经绿果期、转色期到成熟期逐渐降至最低值(126.11 μg/g)。(2)‘赤霞珠’果实发育时期样本转录组测序共获得可能与苹果酸生物合成途径12种功能基因结合的转录因子6 411个,其中延胡索酸水化酶(FH)的3个功能基因有86个转录因子,苹果酸脱氢酶(MDH)的10个功能基因有717个转录因子。(3)转录组测序数据及其与有机酸含量WGCNA关联结果的Veen分析确定了‘赤霞珠’果实成熟过程中与苹果酸生物合成相关度最高的3个FH基因(VIT_14s0060g01700、VIT_13s0019g03330、VIT_07s0005g00880)、2个MDH基因(VIT_10s0003g01000、VIT_13s0019g05250)及相应的18个关键转录因子。(4)qRT PCR验证及相关性分析表明, FH基因VIT_13s0019g03330与其转录因子VIT_01s0011g06200、VIT_08s0056g01230以及MDH基因VIT_13s0019g05250与其转录因子VIT_06s0004g04960、VIT_10s0003g02070的表达水平与苹果酸的积累存在显著正相关关系,推测这4个关键转录因子可能通过调控功能基因的转录,综合影响‘赤霞珠’果实苹果酸的生物合成。     

单甲脒农药对模型池塘生态系统群落结构的影响

在３ｍ×１ｍ×１ｍ（Ｖ＝３ｍ３）含有底泥的模型池塘生态系统中研究单脒农药对水生生物群落结构的影晌。规定实验浓度力０、１．５、３．０、６．０和１２．０ｍｇ／Ｌ,每１５ｄ加入１次２５％单甲脒农药水剂,连续加入４次,实验进行２个多月。在实验浓度范围内,童甲脒农药对水生生物群落产生不同程度的影响。浮游生物比较敏感：加药后头几天内,种类、数量及多样性指数下降,浓度越大,影响越明显;大约１周以后,各处理组浮游生物群落逐步得到恢复,实验后期其数量甚至可超过对照水平,但群落结构发生改变,敏感种类少或消失,耐污种类增加,生物多样性降低。底栖生物比较耐污：处理槽大型水生植物的叶绿素含量有所减少,但其种类和生物量未见明显差异;底栖动物种类、数量也未见明显变化。微生物最耐污,在处理槽水层及沉积物中好氧异养菌数量有所增加,沉积物中厌气菌数量也有增加的趋势。青鱼对单甲脒农药较敏感,在１．５ｍｇ／Ｌ以下浓度尚能正常存活和繁殖。单甲脒农药水剂明显增加水体氮、磷含量,尤其磷酸盐含量高,使水体氮、磷比例失调,可能导致水体富营养化。根据综合指标分析,在规定单甲脒盆酸盐浓度＜１．５ｍｇ／Ｌ的实验条件下,水生生物群落结构未见明显改变．     

RILP suppresses invasion of breast cancer cells by modulating the activity of RalA through interaction with RalGDS

RILP (Rab7-interacting lysosomal protein) is a key regulator for late endosomal/lysosomal trafficking, and probably a tumor suppressor in prostate cancer. However, the role of RILP in other cancers and the underlying mechanism for RILP in regulating the invasion of cancer cells remain to be investigated. In this study, we showed that overexpression of RILP in breast cancer cells inhibits the migration and invasion, whereas the depletion of RILP by RNAi-mediated knockdown promotes the migration and invasion. We identified RalGDS (Ral guanine nucleotide dissociation stimulator) as a novel interacting partner for RILP, and truncation analysis revealed the N-terminal region of RILP is responsible for interacting with the guanine nucleotide exchange factor (GEF) domain of RalGDS. Immunofluorescence microscopy revealed that RalGDS can be recruited to the late endosomal compartments by RILP. Further investigations indicated that the overexpression of RILP inhibits the activity of RalA, a downstream target of RalGDS. Our data suggest that RILP suppresses the invasion of breast cancer cells by interacting with RalGDS to inhibit its GEF activity for RalA.Diverse alternations of oncogenic factors can either activate or inactivate signaling pathways involved in cell proliferation, migration and apoptosis that are intimately associated with cancer development.^{1, 2, 3} Recent studies suggest that the derailed membrane trafficking is also closely related to cancer development. Activation or attenuation of signal transduction is usually linked to membrane trafficking. The recycling and degradation of surface receptors, such as EGFR, will influence downstream signaling pathways.^{4, 5} Therefore, the cross-talk between membrane trafficking and signaling pathway could be the novel mechanism associated with cancer development.Alternations of the membrane trafficking machineries are established as the causes for some cancers. For examples, Rab25 is overexpressed in breast and ovary caners,⁶ and recent investigations suggest that Rab25 is also related to other cancers.^{7, 8, 9} Arf6 is a vital regulator for the invasive activity of breast cancer cells.¹⁰ Disordered membrane trafficking is emerging as an important property during tumorigenesis, thus the membrane trafficking machineries are potential therapeutic targets for cancer treatment.Rab small GTPases are considered as the master regulators for membrane trafficking.¹¹ The interactions between Rab proteins and their downstream effectors are involved in various steps of vesicle trafficking such as tethering and fusion. Aberrant activities of Rab proteins are closely related to some cancers.^{12, 13, 14, 15} Some Rab proteins mediate the trafficking of cargos, especially membrane proteins on the plasma membrane, such as integrin and E-cadherin. Their aberrant trafficking is proposed to be the underlying mechanism for the functional regulation of Rab protein in cancer cells.^{16, 17}Rab7, together with its downstream effector RILP (Rab7-interacting lysosomal protein), are the key regulators for late endosomal/lysosomal trafficking. RILP interacts with activated GTP-bound Rab7 through its carboxylic terminal region, whereas interacting with dynein/dynactin complex is mediated through its amino region, driving late endosomal/lysosomal trafficking, especially lysosomal positioning.^{18, 19} Rab7 has been demonstrated to be an important factor for cell growth and survival.^{20, 21} Recently, Steffan et al.²² found that RILP suppresses the invasion of prostate cancer cells through inhibiting the anterograde trafficking of lysosomes.²³ Whether the potential role of Rab7-RILP in cell migration/invasion is also implicated in other cancers is of interest to investigate and the underlying molecular mechanism is yet to be defined.In this study, we found that RILP suppresses the proliferation, migration and invasion of breast cancer cells. We also identified (Ral guanine nucleotide dissociation stimulator (RalGDS) as a novel interacting partner for RILP. The interaction of RILP with RalGDS modulates the activity of RalA. Our results suggest that RILP suppresses the invasion of breast cancer cells by modulating the activity of RalA through interaction with RalGDS.     

Affinity biosensor for avidin using a double functionalized dendrimer monolayer on a gold electrode

We have developed an affinity biosensor system based on avidin-biotin interaction on a gold electrode. As the building block of an affinity-sensing monolayer, a fourth-generation (G4) poly(amidoamine) dendrimer having partial ferrocenyl-tethered surface groups was prepared and used. The unmodified surface amine groups from dendrimers were functionalized with biotinamidocaproate, and the biotinylated and electroactive dendritic monolayer was constructed on a gold electrode for the affinity-sensing surface interacting with avidin. An electrochemical signal from the affinity biosensor was generated by free glucose oxidase in electrolyte, depending on the degree of coverage of the sensing surface with avidin. The sensor signal decreased correlatively with increasing avidin concentration and approached a minimum level when the sensing surface was fully covered with avidin. The detection limit of avidin was about 4.5 pM, and the sensor signal was linear ranging from 1.5 pM to 10 nM under optimized conditions. From the kinetic analysis using the biotinylated glucose oxidase, an active enzyme coverage of 2.5 x 10(-12) mol/cm(2) on the avidin-pretreated surface was registered, which demonstrates the formation of a spatially ordered and compact protein layer on the derivatized electrode surface.