BACKGROUND & AIMS: :The prevailing hypothesis of lipid droplet biogenesis proposes that neutral lipids accumulate within the lipid bilayer of the ER membrane from where they are budded off, enclosed by a protein-bearing phospholipid monolayer originating from the cytoplasmic leaflet of the ER membrane. We have used a variety of methods to investigate the nature of the sites of ER-lipid-droplet association in order to gain new insights into the mechanism of lipid droplet formation and growth. The three-dimensional perspectives provided by freeze-fracture electron microscopy demonstrate unequivocally that at sites of close association, the lipid droplet is not situated within the ER membrane; rather, both ER membranes lie external to and follow the contour of the lipid droplet, enclosing it in a manner akin to an egg cup (the ER) holding an egg (the lipid droplet). Freeze-fracture cytochemistry demonstrates that the PAT family protein adipophilin is concentrated in prominent clusters in the cytoplasmic leaflet of the ER membrane closely apposed to the lipid droplet envelope. We identify these structures as sites at which lipids and adipophilin are transferred from ER membranes to lipid droplets. These findings call for a re-evaluation of the prevailing hypothesis of lipid droplet biogenesis.

背景与目标： ：脂滴生物发生的普遍假设提出，中性脂质在ER膜的脂质双层中积聚，从那里发芽，并被源自ER膜细胞质小叶的带有蛋白质的磷脂单层包围。我们已经使用多种方法来研究内质网-脂质-液滴缔合的位点的性质，以便获得对脂质液滴形成和生长机理的新见解。冷冻断裂电子显微镜提供的三维立体图清楚地表明，在紧密结合的部位，脂质滴并不位于ER膜内。而是，两个ER膜都位于脂质滴的外部并遵循该滴的轮廓，以类似于容纳鸡蛋（脂质滴）的蛋杯（ER）的方式将其包围。冷冻-断裂细胞化学表明，PAT家族蛋白脂亲蛋白集中在ER膜的细胞质小叶中与脂质小滴包膜紧密相关的突出簇中。我们将这些结构鉴定为脂质和脂肪蛋白从ER膜转移到脂质液滴的位点。这些发现要求对脂滴生物发生的普遍假设进行重新评估。

BACKGROUND & AIMS: The amino-terminal segment of the membrane-anchored subunit of influenza hemagglutinin (HA) plays a crucial role in membrane fusion and, hence, has been termed the fusion peptide. We have studied the secondary structure, orientation, and effects on the bilayer structure of synthetic peptides corresponding to the wild-type and several fusogenic and nonfusogenic mutants with altered N-termini of the influenza HA fusion peptide by fluorescence, circular dichroism, and Fourier transform infrared spectroscopy. All peptides contained segments of alpha-helical and beta-strand conformation. In the wild-type fusion peptide, 40% of all residues were in alpha-secondary and 30% in beta-secondary structures. By comparison, the nonfusogenic peptides exhibited larger beta/alpha secondary structure ratios. The order parameters of the helices and the amide carbonyl groups of the beta-strands of the wild-type fusion peptide were measured separately, based on the infrared dichroism of the respective absorption bands. Order parameters in the range 0.1-0.7 were found for both segments of the wild-type peptide, which indicates that they are most likely aligned at oblique angles to the membrane normal. The nonfusogenic but not the fusogenic peptides induced splitting of the infrared absorption band at 1735 cm(-1), which is assigned to stretching vibrations of the lipid ester carbonyl bond. This splitting, which reports on an alteration of the hydrogen bonds formed between the lipid ester carbonyls and water and/or hydrogen-donating groups of the fusion peptides, correlated with the beta/alpha ratio of the peptides, suggesting that unpaired beta-strands may replace water molecules and hydrogen-bond to the lipid ester carbonyl groups. The profound structural changes induced by single amino acid replacements at the extreme N-terminus of the fusion peptide further suggest that tertiary or quaternary structural interactions may be important when fusion peptides bind to lipid bilayers.

背景与目标： 流感血凝素（HA）的膜锚定亚基的氨基末端片段在膜融合中起着至关重要的作用，因此被称为融合肽。我们已经通过荧光，圆二色性和傅里叶变换研究了对应于野生型和几个融合和非融合突变体的流感病毒HA融合肽的N末端改变的二级肽的二级结构，方向及其对双层肽结构的影响。红外光谱。所有肽都包含α-螺旋和β-链构象的区段。在野生型融合肽中，所有残基的40％在α-二级结构中，而30％在β-二级结构中。相比之下，非融合肽表现出较大的β/α二级结构比。基于各个吸收带的红外二色性，分别测量野生型融合肽的β链的螺旋和酰胺羰基的有序参数。对于野生型肽的两个片段，发现有序参数在0.1-0.7范围内，这表明它们最有可能以与膜法线倾斜的角度排列。非融合肽而非融合肽诱导了1735 cm（-1）处的红外吸收带的分裂，这被分配给了脂质酯羰基键的拉伸振动。该分裂报告了脂质酯羰基与融合肽的水和/或供氢基团之间形成的氢键的改变，与肽的β/α比率相关，表明未配对的β链可能取代水分子，并与脂质酯的羰基氢键合。融合肽极端N端由单个氨基酸置换引起的深刻结构变化进一步表明，当融合肽结合脂质双层时，三级或四级结构相互作用可能很重要。

BACKGROUND & AIMS: The effect of bacteriorhodopsin (BR) on the percolation properties of dimyristoylphosphatidylcholine/distearoylphosphatidylcholine bilayers was examined by studying the quenching of a lipid-bound fluorophore by a lipid-bound quencher, and by spin-spin interactions of a nitroxide-labeled lipid using electron spin resonance (ESR). At the low concentrations of BR used, differential scanning calorimetry showed that although the transition enthalpy was reduced in a concentration-dependent manner by incorporation of BR, the solidus and fluidus phase boundaries and overall shape of the heat capacity profiles were essentially unchanged. However, fluorescence quenching and spin-label ESR data showed that the domain topology, as reflected in the percolation properties, is strongly affected by the protein. In contrast to our previous fluorescence data for the pure lipid mixtures, quenching in the coexistence region is independent of the fluid phase fraction when BR is present. In addition, the percolation threshold estimated by spin-label ESR is shifted in the presence of BR to a higher gel phase fraction at a given lipid composition. Both the fluorescence quenching and spin-label ESR data, together with the results of earlier simulations, strongly suggest that the fluid phase domains are substantially larger and/or less ramified in the presence of BR than in its absence. We have previously reported a similar effect of a transmembrane peptide, pOmpA (Escherichia coli outer membrane protein A signal peptide), on fluid domain connectivity in binary phosphatidylcholine mixtures.

背景与目标： 通过研究脂质结合的猝灭剂对脂质结合的荧光团的猝灭以及使用电子自旋的一氧化氮标记的脂质的自旋旋转相互作用，研究了细菌视紫红质（BR）对二肉豆蔻酰基磷脂酰胆碱/二硬脂酰磷脂酰胆碱双层渗透特性的影响。共振（ESR）。在使用低浓度的BR时，差示扫描量热法显示，尽管通过掺入BR以一定的浓度依赖性降低了转变焓，但固相线和液相线的边界和热容曲线的总体形状基本不变。但是，荧光猝灭和自旋标记ESR数据表明，渗透特性所反映的域拓扑结构受到蛋白质的强烈影响。与我们以前的纯脂质混合物的荧光数据相反，当存在BR时，共存区域的猝灭与液相分数无关。另外，在给定脂质组成下，在BR的存在下，自旋标记ESR估计的渗透阈值会转移到较高的凝胶相分数。荧光猝灭和自旋标记ESR数据以及早期模拟的结果都强烈表明，在存在BR的情况下，与不存在BR的情况相比，液相域的分支和/或分枝显着增加。我们以前曾报道过跨膜肽pOmpA（大肠杆菌外膜蛋白A信号肽）对二元磷脂酰胆碱混合物中的流体域连通性具有类似作用。

BACKGROUND & AIMS: :Inborn errors of vitamin B(12) (cobalamin) metabolism are characterized by decreased production of active cobalamin cofactors and subsequent deficiencies in the activities of methionine synthase and methylmalonyl-CoA mutase. With the recent discovery of the cblJ defect in two patients with phenotypes mimicking the cblF defect, there are nine genes known to be involved in cobalamin metabolism. The new defect is caused by mutations in the ABCD4 gene, encoding an ABC transporter. At the moment, there is no clear distinction between the cblJ and cblF defects either clinically or biochemically, and both defects result in blocks in the transport of cobalamin from the lysosome to the cytoplasm. A patient was diagnosed with hyperhomocysteinemia and methylmalonic aciduria at the age of 8 years. Incorporations of both [(14)C]propionate and [(14)C]methyltetrahydrofolate in cultured fibroblasts were within reference ranges and thus too high to allow for complementation analysis. We observed decreased synthesis of both adenosylcobalamin and methylcobalamin and accumulation of unmetabolized cyanocobalamin. Exome sequencing was performed to identify causative mutation(s) and Sanger re-sequencing was performed to validate segregation of mutation in the family. By this approach, a homozygous mutation, c.423C>G, in the ABCD4 gene was identified. Here, we report the successful application of exome sequencing for diagnosis of a rare inborn error of vitamin B(12) metabolism in a patient whose unusual presentation precluded diagnosis using standard biochemical and genetic approaches. The patient represents only the third known patient with the cblJ disorder.

背景与目标： ：维生素B（12）（钴胺素）代谢的先天性错误的特征在于活性钴胺素辅因子的产生减少以及蛋氨酸合酶和甲基丙二酰辅酶A突变酶的活性随后不足。随着最近在两名模仿cblF缺陷的表型患者中发现cblJ缺陷，已知有9个基因与钴胺素代谢有关。新的缺陷是由编码ABC转运蛋白的ABCD4基因突变引起的。目前，在临床或生化方面，cblJ和cblF缺陷之间尚无明确区分，并且两种缺陷均导致钴胺素从溶酶体到细胞质的转运受阻。一名患者在8岁时被诊断出患有高同型半胱氨酸血症和甲基丙二酸尿症。 [（14）C]丙酸酯和[（14）C]甲基四氢叶酸在培养的成纤维细胞中的掺入均在参考范围内，因此含量过高，无法进行互补分析。我们观察到腺苷钴胺素和甲基钴胺素的合成减少以及未代谢的氰钴胺素的积累。进行了外显子组测序以鉴定致病突变，并进行了桑格重测序以验证家族中突变的分离。通过这种方法，鉴定出ABCD4基因中的纯合突变，即c.423C> G。在这里，我们报告外显子组测序成功诊断了罕见的先天性维生素B（12）代谢错误的患者，该患者的异常表现使得无法使用标准生化和遗传方法进行诊断。该患者仅代表第三位已知的cblJ疾病患者。

BACKGROUND & AIMS: :Effects of chlorobenzene-induced alteration in glutathione levels on cysteine metabolism in rat liver were investigated. Male Wistar rats were intraperitoneally injected with chlorobenzene (0.2, 0.5, 1.0 or 2.0 mmol/kg body weight). Both hepatic glutathione and cysteine levels were dose-dependently decreased by the chlorobenzene 6 h after the injection. However, at 24 h, the glutathione in the rats with chlorobenzene increased significantly as compared to that in the rats without chlorobenzene. Concomitant to the elevation in glutathione levels, hepatic glutathione synthesis activities were increased by the chlorobenzene by 68-111%. On the other hand, no significant difference between the rats with and without chlorobenzene was observed as regards cysteine levels at 24 h. Hepatic glutamate, glycine, methionine and serine levels were unaltered but hepatic taurine levels were significantly decreased by the chlorobenzene at both 6 and 24 h. Chlorobenzene administration had no effect on hepatic cystathionine synthase and cystathionase activities. These results indicate that a transient loss of hepatic glutathione, caused by the administration of chlorobenzene, resulted in an acceleration of glutathione synthesis and an increase of cysteine demand in the liver.

背景与目标： ：研究了氯苯诱导的谷胱甘肽水平改变对大鼠肝脏半胱氨酸代谢的影响。给雄性Wistar大鼠腹膜内注射氯苯（0.2、0.5、1.0或2.0mmol / kg体重）。注射后6小时，氯苯引起的肝谷胱甘肽和半胱氨酸水平均呈剂量依赖性下降。然而，在24小时时，与不含氯苯的大鼠相比，含氯苯的大鼠中的谷胱甘肽显着增加。伴随谷胱甘肽水平的升高，氯苯使肝谷胱甘肽合成活性提高了68-111％。另一方面，在有和没有氯苯的大鼠之间，在24小时的半胱氨酸水平上没有观察到显着差异。肝谷氨酸，甘氨酸，蛋氨酸和丝氨酸水平未改变，但在6和24 h时，氯苯可显着降低肝牛磺酸水平。施用氯苯对肝脏胱硫醚合酶和胱硫醚酶活性没有影响。这些结果表明，由于施用氯苯引起的肝谷胱甘肽的瞬时损失，导致谷胱甘肽合成的加速和肝脏中半胱氨酸需求的增加。

BACKGROUND & AIMS: :Previous work has demonstrated the feasibility of in vivo biodiesel synthesis in Escherichia coli, however, ethyl ester formation was dependent on an external fatty acid feedstock. In contrast to E. coli, actinomycetes may be ideal organisms for direct biodiesel synthesis because of their capacity to synthesize high levels of triacylglcerides (TAGs). In this study, we investigated the physiology and associated TAG accumulation along with the in vivo ability to catalyze ester formation from exogenous short chain alcohol sources in Gordonia sp. KTR9, a strain that possesses a large number of genes dedicated to fatty acid and lipid biosynthesis. Total lipid fatty acids content increased by 75 % and TAG content increased by 50 % under nitrogen starvation conditions in strain KTR9. Strain KTR9 tolerated the exogenous addition of up to 4 % methanol, 4 % ethanol and 2 % propanol in the media. Increasing alcohol concentrations resulted in a decrease in the degree of saturation of recovered fatty acid alcohol esters and a slight increase in the fatty acid chain length. A linear dose dependency in fatty alcohol ester synthesis was observed in the presence of 0.5-2 % methanol and ethanol compared to control KTR9 strains grown in the absence of alcohols. An inspection of the KTR9 genome revealed the presence of several putative wax ester synthase/acyl-coenzyme A : diacylglycerol acyltransferase (WS/DGAT) enzymes, encoded by atf gene homologs, that may catalyze the in vivo synthesis of fatty acid esters from short chain alcohols. Collectively, these results indicate that Gordonia sp. KTR9 may be a suitable actinomycete host strain for in vivo biodiesel synthesis.

背景与目标： ：先前的工作证明了在大肠杆菌中体内生物柴油合成的可行性，但是，乙酯的形成取决于外部脂肪酸原料。与大肠杆菌相反，放线菌可能是直接生物柴油合成的理想生物，因为它们能够合成高含量的三酰基甘油（TAGs）。在这项研究中，我们调查了生理和相关的TAG积累以及体内催化Gordonia sp。中外源短链醇源形成酯的能力。 KTR9，具有大量致力于脂肪酸和脂质生物合成的基因的菌株。在氮饥饿条件下，菌株KTR9的总脂质脂肪酸含量增加了75％，TAG含量增加了50％。菌株KTR9耐受培养基中外源添加多达4％的甲醇，4％的乙醇和2％的丙醇。醇浓度的增加导致回收的脂肪酸醇酯的饱和度降低，并且脂肪酸链长度略微增加。与在不存在醇的情况下生长的对照KTR9菌株相比，在存在0.5-2％的甲醇和乙醇的条件下观察到脂肪醇酯合成的线性剂量依赖性。对KTR9基因组的检查表明存在几种假定的蜡酯合酶/酰基辅酶A：二酰基甘油酰基转移酶（WS / DGAT）酶，这些酶由atf基因同源物编码，可能催化体内短链脂肪酸酯的合成酒精。总的来说，这些结果表明Gordonia sp。 KTR9可能是适合体内生物柴油合成的放线菌宿主菌株。

BACKGROUND & AIMS: :Cancer is a disease of unregulated cell growth and survival, and tumors reprogram biochemical pathways to aid these processes. New capabilities in the computational and bioanalytical characterization of metabolism have now emerged, facilitating the identification of unique metabolic dependencies that arise in specific cancers. By understanding the metabolic phenotype of cancers as a function of their oncogenic profiles, metabolic engineering may be applied to design synthetically lethal therapies for some tumors. This process begins with accurate measurement of metabolic fluxes. Here we review advanced methods of quantifying pathway activity and highlight specific examples where these approaches have uncovered potential opportunities for therapeutic intervention.

背景与目标： ：癌症是细胞生长和存活不受控制的疾病，肿瘤会重编程生化途径来辅助这些过程。现在已经出现了在代谢的计算和生物分析表征中的新功能，从而有助于识别在特定癌症中出现的独特代谢依赖性。通过了解癌症的代谢表型作为其致癌特征的函数，可以将代谢工程应用于某些肿瘤的合成致死疗法的设计。此过程从准确测量代谢通量开始。在这里，我们回顾了量化途径活性的先进方法，并重点介绍了这些方法已发现潜在的治疗干预机会的具体例子。

BACKGROUND & AIMS: BACKGROUND:Microbial oil is one important bio-product for its important function in energy, chemical, and food industry. Finding suitable substrates is one key issue for its industrial application. Both hydrophilic and hydrophobic substrates can be utilized by oleaginous microorganisms with two different bio-pathways ("de novo" lipid fermentation and "ex novo" lipid fermentation). To date, most of the research on lipid fermentation has focused mainly on only one fermentation pathway and little work was carried out on both "de novo" and "ex novo" lipid fermentation simultaneously; thus, the advantages of both lipid fermentation cannot be fulfilled comprehensively. RESULTS:In this study, corncob acid hydrolysate with soybean oil was used as a mix-medium for combined "de novo" and "ex novo" lipid fermentation by oleaginous yeast Trichosporon dermatis. Both hydrophilic and hydrophobic substrates (sugars and soybean oil) in the medium can be utilized simultaneously and efficiently by T. dermatis. Different fermentation modes were compared and the batch mode was the most suitable for the combined fermentation. The influence of soybean oil concentration, inoculum size, and initial pH on the lipid fermentation was evaluated and 20 g/L soybean oil, 5% inoculum size, and initial pH 6.0 were suitable for this bioprocess. By this technology, the lipid composition of extracellular hydrophobic substrate (soybean oil) can be modified. Although adding emulsifier showed little beneficial effect on lipid production, it can modify the intracellular lipid composition of T. dermatis. CONCLUSIONS:The present study proves the potential and possibility of combined "de novo" and "ex novo" lipid fermentation. This technology can use hydrophilic and hydrophobic sustainable bio-resources to generate lipid feedstock for the production of biodiesel or other lipid-based chemical compounds and to treat some special wastes such as oil-containing wastewater.

背景与目标： 背景：微生物油因其在能源，化工和食品工业中的重要作用而成为一种重要的生物产品。寻找合适的基材是其工业应用的关键问题之一。具有两种不同生物途径（“从头”脂质发酵和“从头”脂质发酵）的油脂性微生物均可利用亲水性和疏水性底物。迄今为止，大多数关于脂质发酵的研究主要集中在仅一种发酵途径上，并且很少同时进行“从头”和“从头”脂质发酵的工作。因此，不能同时实现两种脂质发酵的优点。
结果：在这项研究中，玉米芯酸与大豆油的水解产物被用作混合培养基，用于油脂性酵母曲氏菌（Trichosporon dermatis）的“从头”和“从头”组合脂质发酵。皮肤癣菌可同时有效地利用培养基中的亲水性和疏水性底物（糖和大豆油）。比较了不同的发酵模式，分批模式最适合组合发酵。评估了豆油浓度，接种量和初始pH对脂质发酵的影响，并且20 g / L豆油，5％接种量和pH 6.0适于此生物工艺。通过该技术，可以修饰细胞外疏水性底物（大豆油）的脂质组成。尽管添加乳化剂对脂质的产生几乎没有有益作用，但它可以改变皮肤炎球菌的细胞内脂质组成。
结论：本研究证明了“从头”和“从头”脂质发酵相结合的潜力和可能性。该技术可以利用亲水和疏水的可持续生物资源来生产脂质原料，以生产生物柴油或其他基于脂质的化合物，并处理某些特殊废物，例如含油废水。

BACKGROUND & AIMS: :The aim of this study was to determine the metabolic response in giant pandas (Ailuropoda melanoleuca) to the consumption of certain parts of bamboo above ground growth. Giant pandas were provisioned with three species of bamboo: Phyllostachys bissetii, of which they only consume the culm (culm group); Bashania fargesii, of which they only consume the leaves (leaf group); and Qiongzhuea opienensis, of which they only consume the shoots (shoot group). The "culm" group absorbed the highest amount of calories and fiber, but was in short energy supply (depressed tricarboxylic acid cycle activity), and high fiber level diet might reduce the digestibility of protein. The "culm" and "leaf" groups absorbed less protein, and had a lower rate of body mass growth than the "shoot" group. Digestion of fiber requires energy input and yields low caloric extraction from the culm and leaf, and protein intake is important for increasing body mass. However, long-term consumption of shoots may have a potentially negative effect on the health because of high protein composition. Therefore, a balanced diet consisting of diverse plant parts of bamboo is important for the overall metabolic function and health of captive giant pandas.

背景与目标： ：这项研究的目的是确定大熊猫（Ailuropoda melanoleuca）对高于地面生长的竹子某些部位的消耗的代谢反应。大熊猫被提供了三种竹子：毛竹楠（Phyllostachys bissetii），它们只食用茎秆（茎秆组）。 shan藜（Bashania fargesii），只食用叶子（叶组）；和琼竹opienensis，他们只消耗芽（拍摄组）。 “茎”类吸收了最高量的卡路里和纤维，但能量供应不足（三羧酸循环活性降低），高纤维饮食可能会降低蛋白质的消化率。 “茎”和“叶”组比“茎”组吸收更少的蛋白质，并且具有较低的体重增长速度。纤维的消化需要能量输入，并且从茎和叶中产生的热量低，蛋白质的摄入对于增加体重很重要。但是，由于高蛋白质组成，长期食用芽可能对健康产生潜在的负面影响。因此，由竹子的不同植物部分组成的均衡饮食对于圈养大熊猫的整体代谢功能和健康至关重要。

BACKGROUND & AIMS: :Key mitochondrial functions such as ATP production, Ca2+ uptake and release, and substrate accumulation depend on the proton electrochemical gradient (ΔμH+) across the inner membrane. Although several drugs can modulate ΔμH+, their effects are hardly reversible, and lack cellular specificity and spatial resolution. Although channelrhodopsins are widely used to modulate the plasma membrane potential of excitable cells, mitochondria have thus far eluded optogenetic control. Here we describe a toolkit of optometabolic constructs based on selective targeting of channelrhodopsins with distinct functional properties to the inner mitochondrial membrane of intact cells. We show that our strategy enables a light-dependent control of the mitochondrial membrane potential (Δψm) and coupled mitochondrial functions such as ATP synthesis by oxidative phosphorylation, Ca2+ dynamics, and respiratory metabolism. By directly modulating Δψm, the mitochondria-targeted opsins were used to control complex physiological processes such as spontaneous beats in cardiac myocytes and glucose-dependent ATP increase in pancreatic β-cells. Furthermore, our optometabolic tools allow modulation of mitochondrial functions in single cells and defined cell regions.

背景与目标： ：线粒体的关键功能（例如ATP的产生，Ca2的吸收和释放以及底物的积累）取决于跨内膜的质子电化学梯度（ΔμH）。尽管几种药物可以调节ΔμH，但其作用几乎不可逆，并且缺乏细胞特异性和空间分辨率。尽管通道视紫红质被广泛用于调节可兴奋细胞的质膜电位，但线粒体迄今仍未进行光遗传学控制。在这里，我们描述了一种基于选择性具有选择性功能的通道视紫红质靶向完整细胞内部线粒体膜的光代谢构建物的工具包。我们表明，我们的策略能够实现线粒体膜电位（Δψm）的光依赖性控制以及耦合的线粒体功能，例如通过氧化磷酸化，Ca2动力学和呼吸代谢的ATP合成。通过直接调节Δψm，靶向线粒体的视蛋白被用于控制复杂的生理过程，例如心肌细胞的自发搏动和胰腺β细胞的葡萄糖依赖性ATP增加。此外，我们的光代谢工具允许调节单个细胞和定义的细胞区域中的线粒体功能。

BACKGROUND & AIMS: :An extract from red ginseng [steamed and dried roots of Panax ginseng C.A. Meyer (RGE)] has been shown to have various actions on physiological functions. The mechanisms by which RGE promotes cholesterol metabolism in the liver are unclear, but RGE decreases the plasma levels of cholesterol. We investigated whether RGE affected the mRNA expression of cholesterol metabolism-related proteins such as cytochrome P450 (CYP)7A1 and bile salt export pump (BSEP) in the liver in hypercholesterolemic rats and rat primary hepatocytes. In-vivo studies showed the upregulation of CYP7A1 mRNA in hypercholesterolemic rats treated with RGE. Treatment with RGE exhibited decreased ratios of low-density lipoprotein-cholesterol to high-density lipoprotein-cholesterol compared with hypercholesterolemia without RGE. In-vitro studies also showed the upregulation of CYP7A1 mRNA and protein levels by the addition of RGE to rat primary hepatocytes. The mRNA levels of BSEP exhibited few changes. The sustained levels of the liver X receptor (LXR) in vivo and the increased levels of LXR in vitro on RGE treatment could be involved in the upregulation of CYP7A1. To clarify the effects of 11 ginsenosides including RGE on the mRNA levels of CYP7A1 and BSEP, we performed in-vitro experiments using rat primary hepatocytes. The ginsenosides Ro, Rg3, Re, Rg1, and Rg2 exhibited increased mRNA levels of CYP7A1. These results suggest that several ginsenosides including RGE promoted cholesterol metabolism due to upregulation of CYP7A1.

背景与目标： ：红参的提取物[人参C.A.的蒸干后的根。 Meyer（RGE）]已显示对生理功能有多种作用。 RGE促进肝脏中胆固醇代谢的机制尚不清楚，但RGE会降低血浆中的胆固醇水平。我们调查了RGE是否会影响高胆固醇血症大鼠和大鼠原代肝细胞肝脏中胆固醇代谢相关蛋白（如细胞色素P450（CYP）7A1和胆盐输出泵（BSEP））的mRNA表达。体内研究显示，用RGE治疗的高胆固醇血症大鼠中CYP7A1 mRNA的上调。与没有RGE的高胆固醇血症相比，RGE治疗显示低密度脂蛋白胆固醇与高密度脂蛋白胆固醇的比率降低。体外研究还显示，通过向大鼠原代肝细胞中添加RGE，CYP7A1 mRNA和蛋白水平上调。 BSEP的mRNA水平几乎没有变化。体内肝脏X受体（LXR）的持续水平和RGE治疗后体外LXR的水平升高可能与CYP7A1的上调有关。为了阐明包括RGE在内的11种人参皂苷对CYP7A1和BSEP mRNA水平的影响，我们使用大鼠原代肝细胞进行了体外实验。人参皂甙Ro，Rg3，Re，Rg1和Rg2的CYP7A1 mRNA水平升高。这些结果表明，几种人参皂苷（包括RGE）由于CYP7A1的上调而促进了胆固醇的代谢。

BACKGROUND & AIMS: :The leaves of «moderately hardy» (spinach), «very hardy» (ivy) and «extremely hardy» (spruce) plants [classification according to Levitt {1980)] show characteristic differences with respect to changes in membrane lipid composition and chloroplast ultrastructure which are correlated with the degree of the frost resistance achieved by each type of tissue during adaptation to sub-zero temperatures. Spinach leaves showed no increase in their total lipid content upon frost hardening. On the contrary, the amount of galactolipids decreased considerably, whereas that of phospholipids only slightly increased. No shift from the saturated palmitic acid to the three-fold unsaturated linolenic acid was observed. The membrane lipid content of ivy leaves and spruce needles increased to a similar extent during frost hardening. However, in contrast to spruce needles, a distinct preferential accumulation of the phospholipids was observed in ivy leaves, resulting in an increased PL/GL ratio. A considerable shift from saturated (palmitic) to unsaturated fatty acids was detected in both plants, due mainly to an increase in the proportion of linoleic acid in ivy and of linolenic acid in spruce. In spite of the considerable increase in lipid content, no increase in chloroplast number per cell could be detected in ivy leaves, although the length of the thylakoids was nearly doubled and the plastids appeared to be in a division stage: however, no real division could ever be observed. On the contrary, an increase in the number of chloroplasts and mitochondria was observed in spruce needles. Membrane augmentation became further evident by the many large invaginations of the chloroplast envelope formed when the frost-hardened leaves of ivy or spruce were exposed to sub-zero temperatures which they could just survive.

背景与目标： ：“中等硬度”（菠菜），“极度坚硬”（ivy）和“极度坚硬”（云杉）植物的叶子[根据Levitt（1980）分类）在膜脂成分和叶绿体变化方面表现出特征差异超微结构，与适应零度以下温度时每种组织的抗冻性程度有关。霜冻硬化后，菠菜叶的总脂质含量没有增加。相反，半乳糖脂的量显着减少，而磷脂的量仅略有增加。没有观察到从饱和的棕榈酸到三倍的不饱和亚麻酸的转变。在霜冻硬化过程中，常春藤叶和云杉针的膜脂含量增加了相似的程度。然而，与云杉针头相反，在常春藤叶中观察到磷脂的明显优先积累，从而导致PL / GL比增加。在这两种植物中均检测到从饱和（棕榈酸）到不饱和脂肪酸的显着变化，这主要是由于常春藤中亚油酸和云杉中亚麻酸的比例增加。尽管脂质含量显着增加，但常春藤叶中未检测到每细胞的叶绿体数量增加，尽管类囊体的长度几乎增加了一倍，质体似乎处于分裂阶段：但是，不能进行真正的分裂曾经被观察到。相反，在云杉针头中观察到叶绿体和线粒体数量增加。当常春藤或云杉的冻干叶子暴露于零度以下的温度下就可以生存时，叶绿体包膜的许多大的浸入使膜的增强变得更加明显。

BACKGROUND & AIMS: :Obesity, diabetes, hypertension, and hyperlipidemia constitute risk factors for morbidity and premature mortality. Based on animal and in vitro studies, resveratrol reverts these risk factors via stimulation of silent mating type information regulation 2 homolog 1 (SIRT1), but data in human subjects are scarce. The objective of this study was to examine the metabolic effects of high-dose resveratrol in obese human subjects. In a randomized, placebo-controlled, double-blinded, and parallel-group design, 24 obese but otherwise healthy men were randomly assigned to 4 weeks of resveratrol or placebo treatment. Extensive metabolic examinations including assessment of glucose turnover and insulin sensitivity (hyperinsulinemic euglycemic clamp) were performed before and after the treatment. Insulin sensitivity, the primary outcome measure, deteriorated insignificantly in both groups. Endogenous glucose production and the turnover and oxidation rates of glucose remained unchanged. Resveratrol supplementation also had no effect on blood pressure; resting energy expenditure; oxidation rates of lipid; ectopic or visceral fat content; or inflammatory and metabolic biomarkers. The lack of effect disagrees with persuasive data obtained from rodent models and raises doubt about the justification of resveratrol as a human nutritional supplement in metabolic disorders.

背景与目标： 肥胖，糖尿病，高血压和高脂血症是发病率和过早死亡的危险因素。根据动物和体外研究，白藜芦醇通过刺激无声交配类型信息调节2同源物1（SIRT1）来逆转这些危险因素，但人类受试者的数据却很少。这项研究的目的是检查高剂量白藜芦醇在肥胖人类受试者中的代谢作用。在随机，安慰剂对照，双盲和平行组设计中，将24名肥胖但其他方面健康的男性随机分配到白藜芦醇或安慰剂治疗4周。在治疗之前和之后进行了广泛的代谢检查，包括评估葡萄糖更新和胰岛素敏感性（高胰岛素正常血糖钳夹）。两组的主要结果指标胰岛素敏感性均无显着性恶化。内源性葡萄糖的产生以及葡萄糖的周转率和氧化率保持不变。补充白藜芦醇对血压也没有影响。静态能量消耗；脂质的氧化速率；异位或内脏脂肪含量；或炎症和代谢生物标志物。缺乏效果与从啮齿动物模型获得的有说服力的数据不同，并引起人们对白藜芦醇作为代谢障碍中人类营养补充剂的合理性的怀疑。

BACKGROUND & AIMS: :Many phytochemicals, the bioactive nonnutrient compounds found in plant foods, possess biologic effects associated with reduced risk of various diseases such as cancer. Genetic variation in pathways affecting absorption, metabolism, and distribution of phytochemicals is likely to influence exposure at the tissue level, thus modifying disease risk in individuals. Few studies have examined these gene-phytochemical interactions in humans. In this review, we discuss the sources of variation in metabolism and disposition of phytochemicals, and focus on two aspects of phytochemical handling that have received some attention: the impact of intestinal bacteria and genetically polymorphic phase II, conjugating enzymes.

背景与目标： ：许多植物性化学物质是植物性食品中发现的具有生物活性的非营养性化合物，具有与降低各种疾病（如癌症）风险相关的生物作用。影响植物化学物质吸收，代谢和分布的途径中的遗传变异可能会影响组织水平的暴露，从而改变个体的疾病风险。很少有研究检查人类中的这些基因-植物化学相互作用。在这篇综述中，我们讨论了植物化学物质代谢和处置变化的来源，并着重研究了受到关注的植物化学物质处理的两个方面：肠道细菌和遗传多态性II期的影响，结合酶。

BACKGROUND & AIMS: It has been established that oxidized LDL (ox-LDL) modifies cytokine secretion by macrophages, for example, by reducing tumor necrosis factor alpha (TNF-(alpha) m-RNA. However, little is known about the effects of oxidized high density lipoprotein (ox-HDL). This study reports the effects of ox-HDL subfractions 2 and 3 (ox-HDL2, ox-HDL3) compared with that of ox-LDL and some products of oxidation (hydroperoxides and aldehydes) on the secretion of TNF-alpha from THP-1 human monocytes derived macrophages in vitro. HDL2, HDL3 and LDL were oxidized with 10 microM Cu++ for 12 h and/or 24 h. Native and oxidized HDL and LDL were incubated for 24 h with macrophages with or without LPS (10 ng/ml) after which TNF-alpha secretion was measured in the culture medium. Lipid hydroperoxides and apolar aldehydes were also incubated with the cells for 2 h following which the medium was replaced and TNF-alpha secretion measured after a further 22 h of incubation. An inhibition of TNF-alpha by ox-HDL2 (p < .05), ox-HDL3 (p < .05) and ox-LDL (p < .05) from THP-1 macrophages was observed in the presence and absence of LPS. This inhibition remained the same after incubation with ox-HDL 12 h and 24 h. Hydroperoxides of linoleic acid did not modify TNF-alpha secretion by cells while five out of eight aldehydes analyzed (2,4-heptadienal, hexanal, 2-nonenal, 2-octenal, 2,4-decadienal) inhibited TNF-alpha secretion (p < .05). These findings demonstrate that ox-HDL, and some of its lipid peroxidation products, plays a role in the modulation of the inflammatory response by macrophages as previously observed for ox-LDL.

背景与目标： 已经确定氧化的LDL（ox-LDL）可以通过减少肿瘤坏死因子α（TNF-αm-RNA）来调节巨噬细胞的细胞因子分泌。但是，对氧化的高密度脂蛋白的作用知之甚少（ox-HDL）。这项研究报告了与ox-LDL和某些氧化产物（氢过氧化物和醛类）相比，ox-HDL亚组分2和3（ox-HDL2，ox-HDL3）对TNF分泌的影响THP-1人单核细胞衍生的α-α体外，将HDL2，HDL3和LDL用10 microM Cu氧化12 h和/或24 h，将天然和氧化的HDL和LDL与有或没有LPS的巨噬细胞孵育24 h （10 ng / ml），然后在培养基中测量TNF-α的分泌，脂质过氧化氢和非极性醛也与细胞一起孵育2小时，然后更换培养基，再过22 h后测量TNF-α的分泌ox-HDL2对TNF-α的抑制作用（p < .05），在存在和不存在LPS的情况下观察到THP-1巨噬细胞的ox-HDL3（p <.05）和ox-LDL（p <.05）。与ox-HDL孵育12小时和24小时后，这种抑制作用保持不变。亚油酸的氢过氧化物不会改变细胞的TNF-α分泌，而分析的八种醛中的五种（2,4-庚二烯醛，己醛，2-壬烯醛，2-辛烯醛，2,4-癸二烯醛）抑制TNF-α分泌（p <.05）。这些发现表明，ox-HDL及其某些脂质过氧化产物在巨噬细胞对炎症反应的调节中起着作用，正如以前对ox-LDL所观察到的一样。