• 【蛋白激酶D2通过NF-κB介导未转化的人结肠上皮细胞中溶血磷脂酸诱导的白介素8的产生。】 复制标题 收藏 收藏
    DOI:10.1152/ajpcell.00308.2006 复制DOI
    作者列表:Chiu TT,Leung WY,Moyer MP,Strieter RM,Rozengurt E
    BACKGROUND & AIMS: :The signaling pathways mediating lysophosphatidic acid (LPA)-stimulated PKD(2) activation and the potential contribution of PKD(2) in regulating LPA-induced interleukin 8 (IL-8) secretion in nontransformed, human colonic epithelial NCM460 cells were examined. Treatment of serum-deprived NCM460 cells with LPA led to a rapid and striking activation of PKD(2), as measured by in vitro kinase assay and phosphorylation at the activation loop (Ser706/710) and autophosphorylation site (Ser876). PKD(2) activation induced by LPA was abrogated by preincubation with selective PKC inhibitors GF-I and Ro-31-8220 in a dose-dependent manner. These inhibitors did not have any direct inhibitory effect on PKD(2) activity. LPA induced a striking increase in IL-8 production and stimulated NF-kappaB activation, as measured by NF-kappaB-DNA binding, NF-kappaB-driven luciferase reporter activity, and IkappaBalpha phosphorylation. PKD(2) gene silencing utilizing small interfering RNAs targeting distinct PKD(2) sequences dramatically reduced LPA-stimulated NF-kappaB promoter activity and IL-8 production. PKD(2) activation is a novel early event in the biological action of LPA and mediates LPA-stimulated IL-8 secretion in NCM460 cells through a NF-kappaB-dependent pathway. Our results demonstrate, for the first time, the involvement of a member of the PKD family in the production of IL-8, a potent proinflammatory chemokine, by epithelial cells.
    背景与目标: :审查了介导溶血磷脂酸(LPA)刺激的PKD(2)激活和PKD(2)在调节LPA诱导的非转化型人结肠上皮NCM460细胞中LPA诱导的白介素8(IL-8)分泌中的潜在作用。用体外LPA处理血清缺乏的NCM460细胞会导致PKD(2)迅速而惊人的活化,这是通过体外激酶测定和活化环(Ser706 / 710)和自磷酸化位点(Ser876)的磷酸化来测量的。通过与选择性PKC抑制剂GF-1和Ro-31-8220呈剂量依赖性方式进行预孵育,可以消除LPA诱导的PKD(2)激活。这些抑制剂对PKD(2)活性没有任何直接的抑制作用。如通过NF-κB-DNA结合,NF-κB驱动的萤光素酶报道分子活性和IkappaBalpha磷酸化所测量,LPA诱导IL-8产量显着增加并刺激NF-κB活化。 PKD(2)基因沉默利用针对不同的PKD(2)序列的小干扰RNA,大大降低了LPA刺激的NF-κB启动子活性和IL-8的产生。 PKD(2)激活是LPA的生物学作用中的一个新的早期事件,并通过NF-κB依赖性途径介导LCM刺激NCM460细胞中IL-8的分泌。我们的结果首次证明,上皮细胞参与了PKD家族成员参与IL-8(一种有效的促炎趋化因子)的生产。
  • 【意大利北部某地区的综合废物管理:堆肥的生产和使用,以及堆肥,土壤和农作物的分析控制。】 复制标题 收藏 收藏
    DOI:10.1080/03601230600857031 复制DOI
    作者列表:Guerini G,Maffeis P,Allievi L,Gigliotti C
    BACKGROUND & AIMS: :Agricultural soils of two Italian maize farms were treated for five years with an industrially produced high-quality compost. Cattle manure and the usual mineral fertilizer were used for comparison purposes. The effects of the organic and mineral fertilizer treatments were studied by analyzing the compost and manure, cultured soils, and harvested material. The grain yield was also determined. Organic fertilization improved soil pH, CEC, content of organic matter and NPK. Soil respiration and N mineralization were found to be higher than in the purely mineral-treated soil. Plant K take-up was improved, whereas grain yield was not affected. It was confirmed that organic fertilization, particularly compost use, maintained and increased soil fertility. The study demonstrated the feasibility of using in loco analytical facilities to follow the entire recycling process-from waste to compost production-and the use of the final product in the field.
    背景与目标: :意大利的两个玉米农场的农业土壤用工业生产的高质量堆肥处理了五年。为了比较,使用了牛粪和通常的矿物肥料。通过分析堆肥和肥料,耕种的土壤和收获的物料,研究了有机肥料和矿物肥料的处理效果。还确定了谷物产量。有机肥改善了土壤的pH,CEC,有机质含量和NPK。发现土壤呼吸和氮矿化比纯矿物处理过的土壤要高。钾素吸收量得到改善,而谷物单产却没有受到影响。可以肯定的是,有机肥,特别是堆肥的使用,保持并增加了土壤肥力。该研究证明了在机车分析设施中使用该方法以跟踪整个回收过程的可行性(从废物到堆肥的生产)以及最终产品在野外的使用。
  • 【B细胞慢性淋巴细胞性白血病患者T细胞中的信号分子和细胞因子产生:氟达拉滨和alemtuzumab治疗的长期效果。】 复制标题 收藏 收藏
    DOI:10.1080/10428190600565503 复制DOI
    作者列表:Kiaii S,Choudhury A,Mozaffari F,Rezvany R,Lundin J,Mellstedt H,Osterborg A
    BACKGROUND & AIMS: :Fludarabine and alemtuzumab are routinely used for treatment of B-cell chronic lymphocytic leukemia (B-CLL). The present study aimed to compare the expression of signaling molecules and cytokine production by T cells of B-CLL patients in long-term unmaintained remission/plateau phase following fludarabine or alemtuzumab treatment with that of indolent/untreated B-CLL patients and healthy donors. The frequency and intensity of TCR-CD3zeta chain, p56lck, p59fyn, ZAP-70, PI3-kinase and interferon (IFN)-gamma/interleukin (IL)-4 production in CD4 and CD8 T cells was examined by flow cytometry. T-cell function was assessed by stimulation with purified protein derivative (PPD) and phytohemagglutinin (PHA). Despite a reduction in number, the expression of IFN-gamma/IL-4 in T-cells in patients was significantly higher than in healthy donors. The intensity of most signaling molecules in treated patients was relatively unaffected vs. healthy donors but lower than untreated-indolent patients. However, the total number of T cells which expressed each of the signaling molecules was decreased in patients, with no difference between fludarabine- and alemtuzumab-treated patients. The T-cell response to PHA but not PPD was reduced in treated patients. The results suggest that, despite some alterations in signaling molecules and a reduction in T-cell number, overall T-cell functions may be relatively well preserved long-term after treatment with fludarabine and alemtuzumab.
    背景与目标: 氟达拉滨和阿仑单抗通常用于治疗B细胞慢性淋巴细胞性白血病(B-CLL)。本研究旨在比较氟达拉滨或alemtuzumab治疗后长期未维持的缓解/高原期的B-CLL患者的信号分子的表达和T细胞的细胞因子产生与惰性/未经治疗的B-CLL患者和健康供体的长期比较。通过流式细胞术检测TCR-CD3zeta链,p56lck,p59fyn,ZAP-70,PI3-激酶和干扰素(IFN)-γ/白介素(IL)-4在CD4和CD8 T细胞中的产生频率和强度。通过用纯化的蛋白质衍生物(PPD)和植物血凝素(PHA)刺激来评估T细胞功能。尽管数量减少,但患者T细胞中IFN-γ/ IL-4的表达明显高于健康供体。与健康供体相比,已治疗患者中大多数信号分子的强度相对未受影响,但低于未治疗的惰性患者。但是,表达每种信号分子的T细胞总数在患者中减少了,在氟达拉滨和阿仑单抗治疗的患者之间没有差异。在治疗的患者中,对PHA而非TPD的T细胞反应降低。结果表明,尽管在用氟达拉滨和阿仑单抗治疗后,长期而言,尽管信号分子发生了某些变化并且T细胞数量有所减少,但总体T细胞功能仍可以得到较好的保留。
  • 【JTE-607是一种多种细胞因子产生抑制剂,可改善SCID小鼠异种移植急性髓细胞白血病模型中的疾病。】 复制标题 收藏 收藏
    DOI:10.1016/j.exphem.2006.05.016 复制DOI
    作者列表:Uesato N,Fukui K,Maruhashi J,Tojo A,Tajima N
    BACKGROUND & AIMS: OBJECTIVE:Accumulating findings suggest that in acute myeloid leukemia (AML) patients, proinflammatory cytokines and growth factors play important roles in the proliferation and survival of AML cells in an autocrine and paracrine manner, leading to deterioration of AML. JTE-607 is a multiple cytokine inhibitor that potently suppresses production of proinflammatory cytokines. In the present study, we investigated the potency of JTE-607 as an antileukemic agent by exploiting a SCID mouse acute leukemia model. METHODS:SCID mice injected with anti-asialo-GM1 antibody were exposed to sublethal total-body irradiation at a dose of 3 Gy and then inoculated intravenously with AML cells. JTE-607 was administered using osmotic minipumps. The effects of JTE-607 on mouse survival time, human interleukin (IL)-8 levels in mouse plasma, and proportion of human CD45(+) cells in the bone marrow were studied. RESULTS:The survival time of the mice was strictly dependent on the number of U-937 cells proliferating in vivo. Administration of JTE-607 during the initial 7 days significantly prolonged survival of the mice, suggesting killing activity of JTE-607 against AML cells in vivo. Delayed administration of JTE-607 also prolonged the survival of mice bearing established leukemia with an effect comparable to the maximum tolerable dose of cytarabine. Flow cytometer analysis of bone marrow cells revealed decreased number of human CD45(+) cells. Human IL-8 level was also reduced by JTE-607. CONCLUSION:Our results indicate that JTE-607 has potential to be a new class of antileukemic drug that exerts inhibitory activities against both the proliferation and proinflammatory cytokine production of AML cells.
    背景与目标: 目的:大量研究结果表明,在急性髓细胞性白血病(AML)患者中,促炎性细胞因子和生长因子以自分泌和旁分泌方式在AML细胞的增殖和存活中起重要作用,从而导致AML恶化。 JTE-607是一种多细胞因子抑制剂,可有效抑制促炎细胞因子的产生。在本研究中,我们通过利用SCID小鼠急性白血病模型研究了JTE-607作为抗白血病药物的效力。
    方法:将注射了抗亚洲人GM1抗体的SCID小鼠暴露于3 Gy剂量的亚致死性全身照射下,然后静脉注射AML细胞。 JTE-607使用渗透微型泵进行管理。研究了JTE-607对小鼠存活时间,小鼠血浆中人白介素(IL)-8水平以及骨髓中人CD45()细胞比例的影响。
    结果:小鼠的存活时间严格取决于体内增殖的U-937细胞数量。在最初的7天中施用JTE-607可以显着延长小鼠的存活期,表明JTE-607在体内对AML细胞具有杀伤活性。 JTE-607的延迟给药也延长了已确诊白血病的小鼠的存活,其作用与阿糖胞苷的最大耐受剂量相当。骨髓细胞的流式细胞仪分析显示人类CD45()细胞数量减少。 JTE-607也降低了人IL-8水平。
    结论:我们的结果表明,JTE-607有潜力成为一类新型的抗白血病药物,对AML细胞的增殖和促炎性细胞因子产生均具有抑制作用。
  • 【粟酒裂殖酵母CBS 356的细胞外麦芽糖酶的生理特性和补料分批生产。】 复制标题 收藏 收藏
    DOI:10.1111/j.1567-1364.2006.00091.x 复制DOI
    作者列表:Jansen ML,Krook DJ,De Graaf K,van Dijken JP,Pronk JT,de Winde JH
    BACKGROUND & AIMS: :The fission yeast Schizosaccharomyces pombe CBS 356 exhibits extracellular maltase activity. This activity may be of commercial interest as it exhibited a low pH optimum (3.5) and a high affinity for maltose (Km of 7.0+/-1.8 mM). N-terminal sequencing of the protein indicates that it is the product of the AGL1 gene. Regulation of this gene occurs via a derepression/repression mechanism. In sugar- or nitrogen-limited chemostat cultures, the specific rate of enzyme production (q(p)) was independent of the nature of the carbon source (i.e. glucose or maltose), but synthesis was partially repressed by high sugar concentrations. Furthermore, q(p) increased linearly with specific growth rate (mu) between 0.04 and 0.10 h(-1). The enzyme is easily mass-produced in aerobic glucose-limited fed-batch cultures, in which the specific growth rate is controlled to prevent alcoholic fermentation. In fed-batch cultures in which biomass concentrations of 83 g L(-1) were attained, the enzyme concentration reached 58,000 Units per liter culture supernatant. Extracellular maltase may be used as a dough additive in order to prevent mechanisms such as maltose-induced glucose efflux and maltose-hypersensitivity that occur in maltose-consuming Saccharomyces cerevisiae.
    背景与目标: 裂变酵母粟酒裂殖酵母CBS 356表现出细胞外麦芽糖酶活性。该活性可能具有商业价值,因为它显示出低的最适pH(3.5)和对麦芽糖的高亲和力(Km为7.0 /-1.8 mM)。该蛋白质的N端测序表明它是AGL1基因的产物。该基因的调节通过抑制/抑制机制发生。在糖或氮有限的恒化器培养物中,酶产生的比速率(q(p))与碳源(即葡萄糖或麦芽糖)的性质无关,但高糖浓度会部分抑制合成。此外,q(p)随特定生长率(μ)在0.04和0.10 h(-1)之间线性增加。该酶容易在需氧量有限的补料分批培养中大量生产,其中控制特定的生长速率以防止酒精发酵。在分批补料培养中,生物质浓度达到83 g L(-1),每升培养物上清液中的酶浓度达到58,000单位。胞外麦芽糖酶可以用作生面团添加剂,以防止在消耗麦芽糖的酿酒酵母中发生诸如麦芽糖诱导的葡萄糖外流和麦芽糖超敏反应的机制。
  • 【电刺激通过肝素生物激活的导电支架调节成骨细胞的增殖和骨蛋白的产生。】 复制标题 收藏 收藏
    DOI:10.1002/bem.21766 复制DOI
    作者列表:Meng S,Rouabhia M,Zhang Z
    BACKGROUND & AIMS: :Electrical fields are known to interact with human cells. This principle has been explored to regulate cellular activities for bone tissue regeneration. In this work, Saos-2 cells were cultured on conductive scaffolds made of biodegradable poly(L-lactide) and the heparin-containing, electrically conducting polypyrrole (PPy/HE) to study their reaction to electrical stimulation (ES) mediated through such scaffolds. Both the duration and intensity of ES enhanced cell proliferation, generating a unique electrical intensity and temporal "window" within which osteoblast proliferation was upmodulated in contrast to the downmodulation or ineffectiveness in other ES regions. The favourable ES intensity (200 mV/mm) was further investigated in terms of the gene activation and protein production of two important osteoblast markers characterised by extracellular matrix maturation and mineralisation, that is alkaline phosphatase (ALP) and osteocalcin (OC). Both genes were found activated and the relevant protein production increased significantly following ES. In contrast, ES in the down-modulation region (400 mV/mm) suppressed the production of both ALP and OC. This work demonstrated that important osteoblast markers can be modulated with specific ES parameters mediated through conductive polymer substrates, providing a unique strategy for bone tissue engineering.
    背景与目标: :众所周知,电场会与人类细胞发生相互作用。已经探索了该原理以调节用于骨组织再生的细胞活性。在这项工作中,将Saos-2细胞培养在由可生物降解的聚(L-丙交酯)和含肝素的导电聚吡咯(PPy / HE)制成的导电支架上,以研究它们对通过此类支架介导的电刺激(ES)的反应。 ES的持续时间和强度都增强了细胞增殖,产生了独特的电强度和暂时的“窗口”,其中成骨细胞的增殖被上调,而其他ES区域的下调或无效。根据两个重要的以细胞外基质成熟和矿化为特征的重要成骨细胞标志物,即碱性磷酸酶(ALP)和骨钙蛋白(OC)的基因激活和蛋白质产生,进一步研究了有利的ES强度(200(mV / mm)。发现两个基因均被激活,ES后相关的蛋白质产量显着增加。相反,在下调制区域(400 mV / mm)的ES抑制了ALP和OC的产生。这项工作表明重要的成骨细胞标志物可以通过导电聚合物底物介导的特定ES参数进行调节,从而为骨组织工程学提供了独特的策略。
  • 【体外CO2诱导的ROS产生会损害SH-SY5Y神经母细胞瘤细胞的细胞周期。】 复制标题 收藏 收藏
    DOI:10.1007/s00383-012-3206-3 复制DOI
    作者列表:Montalto AS,Currò M,Russo T,Visalli G,Impellizzeri P,Antonuccio P,Arena S,Borruto FA,Scalfari G,Ientile R,Romeo C
    BACKGROUND & AIMS: PURPOSE:We evaluated in vitro the role of CO(2)-induced oxidative stress on the expression of proteins involved in cell-cycle regulation of neuroblastoma cells. METHODS:SH-SY5Y cells were exposed to CO(2) at 15 mmHg pressure (100 %) for 4 h and then moved to normal condition for 24 h. Control cells were maintained in 5 % CO(2) for the same time. ROS production was determined by fluorescent staining with H2DCF-DA. DNA damage was measured by COMET assay. p53 protein expression was analyzed by western blot and confocal laser scanning microscopy was used to evaluate its sub-cellular localization. Cyclin expression was quantified by real-time PCR and western blot. Cell-cycle analysis was performed by FACS. RESULTS:CO(2) incubation was associated with an increase in ROS production (p < 0.01), cell DNA damage mainly after 24 h (12 % increase of tail DNA content and 4-fold increase of tail length) and a significant up-regulation in p53 expression at 24 h with an intense nuclear staining. In CO(2)-treated cells, we observed an S-phase arrest in correlation with a reduction of cyclin B1 expression. CONCLUSIONS:In vitro-simulated pneumoperitoneum environment with CO(2) induces oxidative stress and cell DNA damage, leading to p53 up-regulation involved in cell-cycle arrest of neuroblastoma cells.
    背景与目标: 目的:我们评估了CO(2)诱导的氧化应激在神经母细胞瘤细胞的细胞周期调控中涉及的蛋白质表达中的作用。
    方法:SH-SY5Y细胞在15mmHg压力(100%)下暴露于CO(2)4小时,然后移至正常状态24小时。对照细胞同时保持在5%CO(2)中。通过用H2DCF-DA进行荧光染色来确定ROS的产生。通过COMET测定法测量DNA损伤。通过蛋白质印迹分析p53蛋白的表达,并使用共聚焦激光扫描显微镜评估其亚细胞定位。通过实时PCR和蛋白质印迹法定量细胞周期蛋白的表达。通过FACS进行细胞周期分析。
    结果:CO(2)孵育与ROS产量增加(p <0.01),细胞DNA损伤主要在24小时后(尾部DNA含量增加12%和尾部长度增加4倍)和显着升高有关。强烈的核染色可在24小时内调节p53表达。在CO(2)处理的细胞中,我们观察到与细胞周期蛋白B1表达减少相关的S期停滞。
    结论:在体外模拟气腹环境中,CO(2)会诱导氧化应激和细胞DNA损伤,从而导致p53上调参与神经母细胞瘤细胞的细胞周期阻滞。
  • 【天然非结构化α-突触核蛋白向其α-螺旋构象的转化显着减弱了活性氧的产生。】 复制标题 收藏 收藏
    DOI:10.1016/j.jinorgbio.2012.09.001 复制DOI
    作者列表:Zhou B,Hao Y,Wang C,Li D,Liu YN,Zhou F
    BACKGROUND & AIMS: :The intracellular α-synuclein (α-syn) protein, whose conformational change and aggregation have been closely linked to the pathology of Parkingson's disease (PD), is highly populated at the presynaptic termini and remains there in the α-helical conformation. In this study, circular dichroism confirmed that natively unstructured α-syn in aqueous solution was transformed to its α-helical conformation upon addition of trifluoroethanol (TFE). Electrochemical and UV-visible spectroscopic experiments reveal that both Cu (I) and Cu (II) are stabilized, with the former being stabilized by about two orders of magnitude. Compared to unstructured α-syn (Binolfi et al., J. Am. Chem. Soc. 133 (2011) 194-196), α-helical α-syn stabilizes Cu (I) by more than three orders of magnitude. Through the measurements of H(2)O(2) and hydroxyl radicals (OH) in solutions containing different forms of Cu (II) (free and complexed by unstructured or α-helical α-syn), we demonstrate that the significantly enhanced Cu (I) binding affinity helps inhibit the production of highly toxic reactive oxygen species, especially the hydroxyl radicals. Our study provides strong evidence that, as a possible means to prevent neuronal cell damage, conversion of the natively unstructured α-syn to its α-helical conformation in vivo could significantly attenuate the copper-modulated ROS production.
    背景与目标: :胞内α-突触核蛋白(α-syn)蛋白的构象变化和聚集与帕金森氏病(PD)的病理状况密切相关,在突触前末端高密度分布,并保持在α-螺旋构象中。在这项研究中,圆二色性证实,加入三氟乙醇(TFE)后,水溶液中的天然非结构化α-syn转变为其α-螺旋构象。电化学和紫外可见光谱实验表明,Cu(I)和Cu(II)都稳定了,前者稳定了大约两个数量级。与非结构化α-syn相比(Binolfi等人,J.Am.Chem.Soc.133(2011)194-196),α-螺旋α-syn使Cu(I)稳定超过三个数量级。通过测量H(2)O(2)和羟基自由基(OH)在包含不同形式的Cu(II)(游离且由非结构化或α-螺旋α-syn络合)的溶液中,我们证明了显着增强的Cu (I)结合亲和力有助于抑制剧毒活性氧的产生,特别是羟基自由基的产生。我们的研究提供了有力的证据,作为一种可能的预防神经元细胞损伤的方法,体内天然非结构化的α-syn转化为其α-螺旋构象可以显着减弱铜调节的ROS产生。
  • 【煤诱导了斯氏假单胞菌生产鼠李糖脂生物表面活性剂,该假单胞菌从Jharia煤层的地层水中分离出来。】 复制标题 收藏 收藏
    DOI:10.1016/j.biortech.2012.10.127 复制DOI
    作者列表:Singh DN,Tripathi AK
    BACKGROUND & AIMS: :A strain of Pseudomonas stutzeri was isolated form an enrichment of perchlorate reducing bacteria from the formation water collected from an Indian coalbed which solubilized coal and produced copious amount of biosurfactant when coal was added to the medium. It produced maximum biosurfactant with lignite coal followed by olive oil and soybean oil which was able to emulsify several aromatic hydrocarbons including kerosene oil, diesel oil, hexane, toluene etc. Haemolytic test, growth inhibition of Bacillus subtilis and FTIR analysis showed rhamnolipid nature of the biosurfactant. The stability of the coal induced biosurfactant in pH range of 4-8 and up to 25% NaCl concentration and 100 °C temperature suggests that due to its ability to produce biosurfactant and solubilize coal P. stutzeri may be useful in the coalbed for in situ biotransformation of coal into methane and in the bioremediation of PAHs from oil contaminated sites including marine environments.
    背景与目标: :从从印度煤层中收集的地层水中分离出富集高氯酸盐的细菌,分离出一株假单胞菌假单胞菌,当将煤添加到培养基中时,该煤层溶解了煤炭并产生了大量生物表面活性剂。它生产的生物表面活性剂最多的是褐煤,其次是橄榄油和大豆油,能够乳化煤油,柴油,己烷,甲苯等几种芳烃。生物表面活性剂。煤炭诱导的生物表面活性剂在4-8的pH范围内以及最高25%的NaCl浓度和100°C的温度下的稳定性表明,由于其具有产生生物表面活性剂和溶解煤炭的能力,斯图哲木可能在原位用于煤层中。煤的生物转化为甲烷,以及在石油污染的地点(包括海洋环境)中对多环芳烃的生物修复。
  • 【用于第二代生物燃料生产的超基因组功能纤维素酶的生物勘探:综述。】 复制标题 收藏 收藏
    DOI:10.1080/1040841X.2017.1337713 复制DOI
    作者列表:Tiwari R,Nain L,Labrou NE,Shukla P
    BACKGROUND & AIMS: :Second generation biofuel production has been appeared as a sustainable and alternative energy option. The ultimate aim is the development of an industrially feasible and economic conversion process of lignocellulosic biomass into biofuel molecules. Since, cellulose is the most abundant biopolymer and also represented as the photosynthetically fixed form of carbon, the efficient hydrolysis of cellulose is the most important step towards the development of a sustainable biofuel production process. The enzymatic hydrolysis of cellulose by suites of hydrolytic enzymes underlines the importance of cellulase enzyme system in whole hydrolysis process. However, the selection of the suitable cellulolytic enzymes with enhanced activities remains a challenge for the biorefinery industry to obtain efficient enzymatic hydrolysis of biomass. The present review focuses on deciphering the novel and effective cellulases from different environmental niches by unculturable metagenomic approaches. Furthermore, a comprehensive functional aspect of cellulases is also presented and evaluated by assessing the structural and catalytic properties as well as sequence identities and expression patterns. This review summarizes the recent development in metagenomics based approaches for identifying and exploring novel cellulases which open new avenues for their successful application in biorefineries.
    背景与目标: :第二代生物燃料生产已被视为一种可持续的替代能源选择。最终目的是开发一种工业上可行且经济的木质纤维素生物质转化为生物燃料分子的方法。由于纤维素是最丰富的生物聚合物,并且也表现为碳的光合作用固定形式,因此纤维素的有效水解是朝着可持续生物燃料生产工艺发展的最重要步骤。一系列水解酶对纤维素的酶促水解强调了纤维素酶系统在整个水解过程中的重要性。然而,选择具有增强活性的合适的纤维素分解酶对于生物精炼工业获得有效的生物质的酶水解仍然是一个挑战。目前的审查侧重于通过不可培养的宏基因组学方法从不同的环境利基破译新颖和有效的纤维素酶。此外,还介绍了纤维素酶的综合功能方面,并通过评估结构和催化特性以及序列同一性和表达模式来对其进行评估。这篇综述总结了基于宏基因组学的方法的最新发展,该方法用于鉴定和探索新型纤维素酶,为它们在生物精炼厂的成功应用开辟了新途径。
  • 【Cissampelos sympodialis Eichl叶片的乙醇提取物的水相部分的支气管扩张活性。 (Menispermaceae)在豚鼠中。】 复制标题 收藏 收藏
    DOI:10.1016/S0944-7113(97)80073-6 复制DOI
    作者列表:Thomas G,Araújo CC,Duarte JC,De Souza DP
    BACKGROUND & AIMS: :The bronchodilator activity of an aqueous fraction (AF) of a 70% hydroalcoholic extract of the leaves of Cissampelos sympodialis Eichl. was evaluated in the guinea-pig. The AF inhibited the spontaneous tone of the trachea (IC(50), 13.9 μg/ml), which was potentiated (IC(50), 4.6 μg/ml) by 3-isobutyl-l-methylxanthine, blocked by β(2) adrenoceptor blocking agent timolol, but unaffected by removal of epithelium or addition of NG-Nitro-L-arginine methyl ester or methylene blue. The AF also antagonized contractions induced by carbachol, capsaicin and arachidonic acid in normal trachea and by ovalbumin in trachea obtained from sensitized guinea-pigs. The IC(50)-values in these experiments varied from 34.1-70.5 μg/ml. Further, the AF (100 mg/kg) by the more effective i.p. route increased the preconvulsive time of animals exposed to an aerosol of histamine to 63.5 ± 5 s 1 h after administration compared to 28 ± 1 s in the untreated group. In addition, the AF at 100 mg/kg i.p. or i.G. protected the sensitized guinea-pigs against anaphylactic shock induced by ovalbumin aerosol by 78.6 and 86.7% respectively.
    背景与目标: :七叶蝉叶的70%的水醇提取物的水相(AF)的支气管扩张活性。在豚鼠中进行了评估。 AF抑制气管的自发音(IC(50),13.9μg/ ml),其被3-异丁基-1-甲基黄嘌呤增强并被β(2)阻断(IC(50),4.6μg/ ml)。肾上腺素受体阻滞剂噻吗洛尔,但不受上皮去除或添加NG-硝基-L-精氨酸甲酯或亚甲基蓝的影响。房颤还拮抗正常气管中卡巴胆碱,辣椒素和花生四烯酸引起的收缩,以及从致敏的豚鼠获得的气管中卵清蛋白引起的收缩。这些实验中的IC(50)值从34.1-70.5μg/ ml不等。此外,AF(100 mg / kg)的腹腔镜效果更佳。给药后1小时,暴露于组胺气溶胶的动物的惊厥前时间延长至63.5±5 s,而未治疗组为28±1 s。此外,AF的i.p.为100 mg / kg。或i.G.致敏豚鼠对卵白蛋白气溶胶引起的过敏性休克的保护作用分别为78.6和86.7%。
  • 【中间链球菌中溶血素产生的血液成分的正控制和负控制途径。】 复制标题 收藏 收藏
    DOI:10.1128/IAI.00379-17 复制DOI
    作者列表:Tomoyasu T,Yamasaki T,Chiba S,Kusaka S,Tabata A,Whiley RA,Nagamune H
    BACKGROUND & AIMS: :Streptococcus intermedius is an opportunistic bacterial pathogen secreting a human-specific cytolysin called intermedilysin (ILY) as a major pathogenic factor. This bacterium can degrade glycans into monosaccharides using two glycosidases, multisubstrate glycosidase A (MsgA) and neuraminidase (NanA). Here, we detected a stronger hemolytic activity mediated by ILY when S. intermedius PC574 was cultured in fetal bovine serum (FBS) than when it was grown in the standard culture medium. FBS-cultured cells also showed higher MsgA and NanA activity, although overproduction of ILY in FBS was undetectable in mutants nanA-null and msgA-null. Addition of purified MsgA and NanA to the FBS resulted in a release of 2.8 mM galactose and 4.3 mM N-acetylneuraminic acid; these sugar concentrations were sufficient to upregulate the expression of ILY, MsgA, and NanA. Conversely, when strain PC574 was cultured in human plasma, no similar increase in hemolytic activity was observed. Moreover, addition of human plasma to the culture in FBS appeared to inhibit the stimulatory effect of FBS on ILY, MsgA, and NanA, although there were individual differences among the plasma samples. We confirmed that human plasma contains immunoglobulins that can neutralize ILY, MsgA, and NanA activities. In addition, human plasma had a neutralizing effect on cytotoxicity of S. intermedius toward HepG2 cells in FBS, and a higher concentration of human plasma was necessary to reduce the cytotoxicity of an ILY-high-producing strain than an ILY-low-producing strain. Overall, our data show that blood contains factors that stimulate and inhibit ILY expression and activity, which may affect pathogenicity of S. intermedius.
    背景与目标: :Intermedococcus intermedius是一种机会细菌性病原体,会分泌称为intermedilysin(ILY)的人类特异性溶细胞素,这是主要的致病因素。该细菌可以使用两种糖苷酶,多底物糖苷酶A(MsgA)和神经氨酸酶(NanA)将聚糖降解为单糖。在这里,与在标准培养基中生长相比,在胎牛血清(FBS)中培养中间链霉菌PC574时,我们检测到由ILY介导的溶血活性更强。 FBS培养的细胞也显示出更高的MsgA和NanA活性,尽管在突变体nanA-null和msgA-null中无法检测到FLY中ILY的过量产生。向FBS中添加纯化的MsgA和NanA导致释放2.8 mM半乳糖和4.3 mM N-乙酰神经氨酸。这些糖浓度足以上调ILY,MsgA和NanA的表达。相反,当在人血浆中培养PC574菌株时,未观察到溶血活性的类似增加。此外,尽管血浆样品之间存在个体差异,但在FBS的培养物中添加人血浆似乎抑制了FBS对ILY,MsgA和NanA的刺激作用。我们证实人血浆中含有可以中和ILY,MsgA和NanA活性的免疫球蛋白。另外,人血浆对中间人链球菌对FBS中的HepG2细胞的细胞毒性具有中和作用,为了降低ILY高产菌株的细胞毒性,需要更高浓度的人血浆来降低ILY高产菌株的细胞毒性。 。总的来说,我们的数据表明血液中含有刺激和抑制ILY表达和活性的因子,这些因子可能影响中间链球菌的致病性。
  • 【通过减轻细胞表面工程酵母菌株对纤维素酶的不可逆吸附,可同时改善结晶纤维素的糖化作用和乙醇生产。】 复制标题 收藏 收藏
    DOI:10.1007/s00253-012-4587-x 复制DOI
    作者列表:Matano Y,Hasunuma T,Kondo A
    BACKGROUND & AIMS: :Enzymatic hydrolysis of cellulosic material is an essential step in the bioethanol production process. However, complete cellulose hydrolysis by cellulase is difficult due to the irreversible adsorption of cellulase onto cellulose. Thus, part of the cellulose remains in crystalline form after hydrolysis. In this study, after 96-h hydrolysis of Avicel crystalline cellulose, 47.1 % of the cellulase was adsorbed on the cellulose surface with 10.8 % crystalline cellulose remaining. In simultaneous saccharification and fermentation of 100 g/L Avicel with 1.0 filter paper unit/mL cellulase, a wild-type yeast strain produced 44.7 g/L ethanol after 96 h. The yield of ethanol was 79.7 % of the theoretical yield. On the other hand, a recombinant yeast strain displaying various cellulases, such as β-glucosidase, cellobiohydrolase, and endoglucanase, produced 48.9 g/L ethanol, which corresponds to 87.3 % of the theoretical yield. Higher ethanol production appears to be attributable to higher efficiency of cellulase displayed on the cell surface. These results suggest that cellulases displayed on the yeast cell surface improve hydrolysis of Avicel crystalline cellulose. Indeed, after the 96-h simultaneous saccharification and fermentation using the cellulase-displaying yeast, the amount of residual cellulose was 1.5 g/L, one quarter of the cellulose remaining using the wild-type strain, a result of the alleviation of irreversible adsorption of cellulases on the crystalline cellulose.
    背景与目标: :纤维素材料的酶水解是生物乙醇生产过程中必不可少的步骤。但是,由于纤维素酶不可逆地吸附在纤维素上,因此很难通过纤维素酶将纤维素完全水解。因此,部分纤维素在水解后保持为结晶形式。在这项研究中,Avicel结晶纤维素水解96小时后,47.1%的纤维素酶被吸附在纤维素表面,而剩余的10.8%结晶纤维素被吸收。在同时用100毫升滤纸单位/ mL纤维素酶糖化和发酵100 g / L Avicel的过程中,一种野生型酵母菌株在96小时后产生了44.7 g / L乙醇。乙醇的产率为理论产率的79.7%。另一方面,展示各种纤维素酶,例如β-葡萄糖苷酶,纤维二糖水解酶和内切葡聚糖酶的重组酵母菌株产生了48.9 g / L乙醇,相当于理论收率的87.3%。较高的乙醇产量似乎归因于细胞表面展示的纤维素酶效率更高。这些结果表明,展示在酵母细胞表面上的纤维素酶改善了Avicel结晶纤维素的水解。实际上,在使用展示纤维素酶的酵母糖进行96小时同步糖化和发酵后,残留纤维素的量为1.5 g / L,其中野生型菌株残留的纤维素的四分之一是减轻不可逆吸附的结果纤维素在结晶纤维素上的分布。
  • 【在空运生物反应器中大规模种植紫锥菊的不定根,用于生产Chichoricic酸,绿原酸和Caftaric酸。】 复制标题 收藏 收藏
    DOI:10.1007/s10529-007-9399-1 复制DOI
    作者列表:Wu CH,Murthy HN,Hahn EJ,Paek KY
    BACKGROUND & AIMS: :Adventitious roots of Echinacea purpurea were cultured in airlift bioreactors (20 l, 500 l balloon-type, bubble bioreactors and 1,000 l drum-type bubble bioreactor) using Murashige and Skoog (MS) medium with 2 mg indole butyric acid l(-1) and 50 g sucrose l(-1) for the production of chichoric acid, chlorogenic acid and caftaric acid. In the 20 l bioreactor (containing 14 l MS medium) a maximum yield of 11 g dry biomass l(-1) was achieved after 60 days. However, the amount of total phenolics (57 mg g(-1) DW), flavonoids (34 mg g(-1) DW) and caffeic acid derivatives (38 mg g(-1) DW) were highest after 50 days. Based on these studies, pilot-scale cultures were established and 3.6 kg and 5.1 kg dry biomass were achieved in the 500 l and 1,000 l bioreactors, respectively. The accumulation of 5 mg chlorogenic acid g(-1) DW, 22 mg chichoric acid g(-1) DW and 4 mg caftaric acids g(-1) DW were achieved with adventitious roots grown in 1,000 l bioreactors.
    背景与目标: :紫锥菊的次生根在装有2 mg吲哚丁酸l(-1)的Murashige和Skoog(MS)培养基中于气举生物反应器(20 l,500 l气球型,气泡生物反应器和1,000 l鼓型气泡生物反应器)中培养。 )和50克蔗糖l(-1)用于生产手性酸,绿原酸和异戊酸。 60天后,在20升生物反应器(包含14升MS培养基)中,最大产量为11克干燥生物质l(-1)。但是,总酚含量(57 mg g(-1)DW),类黄酮(34 mg g(-1)DW)和咖啡酸衍生物(38 mg g(-1)DW)的量在50天后最高。基于这些研究,建立了中试规模的培养,分别在500 l和1,000 l生物反应器中实现了3.6 kg和5.1 kg干燥生物量。 5 mg绿原酸g(-1)DW,22 mg chichoric acid g(-1)DW和4 mg caftaric acid g(-1)DW的积累是通过在1,000升生物反应器中生长的不定根实现的。
  • 【结核病患者皮质醇/脱氢表雄酮比值的变化及其与外周血单核细胞由分枝杆菌驱动的细胞因子产生异常的关系。】 复制标题 收藏 收藏
    DOI:10.1111/j.1365-3083.2007.01952.x 复制DOI
    作者列表:Bozza VV,D'Attilio L,Mahuad CV,Giri AA,Del Rey A,Besedovsky H,Bottasso O,Bay ML
    BACKGROUND & AIMS: :We have investigated the relationship between cortisol and dehydroepiandrosterone (DHEA) levels and the immune response to mycobacterial antigens in peripheral venous blood, from a male population of active tuberculosis patients and age-matched healthy controls of the same sex (HCo). Peripheral blood mononuclear cells were cultured for 36 or 96 h with whole sonicated Mycobacterium tuberculosis (WSA) for measurement of proliferation, interferon gamma (IFN-gamma) and interleukin-10 (IL-10) in culture supernatants. Comparisons on the in vitro mycobacterial-driven immune responses demonstrated that TB patients had a higher IL-10 production, a decreased lymphoproliferation and a trend to reduced IFN-gamma synthesis, in relation to HCo. Active disease was also characterized by increases in the plasma levels of glucocorticoids (GC) and reduced concentrations of DHEA which resulted in a higher cortisol/DHEA ratio respect the HCo group. Plasma DHEA levels were positively correlated with IFN-gamma values. An inverse correlation was found between the cortisol/DHEA ratio and IFN-gamma levels. Novel evidence is provided showing that the balance between cortisol and DHEA is partly responsible for the immune perturbations seen in TB patients.
    背景与目标: :我们研究了男性活跃结核病患者人群和年龄匹配的同性健康对照者(HCo)的皮质醇和脱氢表雄酮(DHEA)水平与外周静脉血对分枝杆菌抗原的免疫反应之间的关系。将外周血单核细胞与全超声分枝杆菌(WSA)培养36或96 h,以测量培养上清液中的增殖,干扰素γ(IFN-γ)和白介素10(IL-10)。体外分枝杆菌驱动的免疫反应的比较表明,与HCo相比,结核病患者具有更高的IL-10产生,降低的淋巴增殖和减少IFN-γ合成的趋势。活动性疾病的特征还在于血浆糖皮质激素(GC)水平升高和DHEA浓度降低,从而导致相对于HCo组更高的皮质醇/ DHEA比。血浆DHEA水平与IFN-γ值呈正相关。发现皮质醇/ DHEA比与IFN-γ水平成反比。提供了新的证据,表明皮质醇和DHEA之间的平衡是造成TB患者免疫紊乱的部分原因。

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