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101.
102.
The regulatory NEMO (NF-κB essential modulator) protein has a crucial role in the canonical NF-κB signaling pathway notably involved in immune and inflammatory responses, apoptosis and oncogenesis. The regulatory domain is located in the C-terminal half of NEMO and contains a classical CCHC-type zinc finger (ZF). We have investigated the structural and functional effects of a cysteine to phenylalanine point mutation (C417F) in the ZF motif, identified in patients with anhidrotic ectodermal dysplasia with immunodeficiency. The solution structures of the wild type and mutant ZF were determined by NMR. Remarkably, the mutant adopts a global ββα fold similar to that of the wild type and retains thermodynamic stability, i.e., the ability to bind zinc with a native-like affinity, although the last zinc-chelating residue is missing. However, the mutation induces enhanced dynamics in the motif and leads to an important loss of stability. A detailed analysis of the wild type solution structure and experimental evidences led to the identification of two possible protein-binding surfaces that are largely destabilized in the mutant. This is sufficient to alter NEMO function, since functional complementation assays using NEMO-deficient pre-B and T lymphocytes show that full-length C417F pathogenic NEMO leads to a partial to strong defect in LPS, IL-1β and TNF-α-induced NF-κB activation, respectively, as compared to wild type NEMO. Altogether, these results shed light onto the role of NEMO ZF as a protein-binding motif and show that a precise structural integrity of the ZF should be preserved to lead to a functional protein-recognition motif triggering full NF-κB activation. 相似文献
103.
Angela Maria Amorini Giuseppe Lazzarino Fabio Galvano Giovanna Fazzina Barbara Tavazzi Giacomo Galvano 《Free radical research》2013,47(4):453-460
The cyanidin-3- O - g -glucopyranoside (C-3-G) antioxidant capacity towards reactive oxygen species (ROS)-mediated damages was assessed in tissue and cells submitted to increased oxidative stress. In the isolated ischemic and reperfused rat heart, 10 or 30 w M C-3-G protected from both lipid peroxidation (66.7 and 94% inhibition of malondialdehyde (MDA) generation in 10 and 30 w M C-3-G-reperfused hearts, respectively, in comparison with control reperfused hearts) and energy metabolism impairment (higher ATP concentration in 10 and 30 w M C-3-G-reperfused hearts than in control reperfused hearts). These effects were associated to C-3-G permeation within myocardial cells, as indicated by results obtained in the isolated rat heart perfused for 30 min in the recirculating Langendorff mode under normoxia with 10 and 30 w M C-3-G. Protective effects were exerted, in a dose-dependent manner, by C-3-G also in 2 mM hydrogen peroxide-treated human erythrocytes. With respect to MDA formation, an apparent IC 50 of 5.12 w M was calculated for C-3-G (the polyphenol resveratrol used for comparison showed an apparent IC 50 of 38.43 w M). The general indications are that C-3-G (largely diffused in dietary plants and fruits, such as pigmented oranges very common in the Mediterranean diet) represents a powerful natural antioxidant with beneficial effects in case of increased oxidative stress, and at pharmacological concentrations it is able to decrease tissue damages occurring in myocardial ischemia and reperfusion. 相似文献
104.
Two lines of the red and pale yellow cell suspension cultures, prepared fromPrunus x yedoensis Matsum. callus induced by Murashige and Skoog's (1962) basal medium supplemented with 2, 4-dichlorophenoxyacetic acid (2,
4-D, 1.0 mg/l), kinetin (0.1 mg/l) and sucrose (30 g/l), were maintained on Schenk and Hildebrandt medium as modified by Mitchell
and Gildow (1975). The red cell suspension culture produced cyanidin 3-monoglucoside, 5, 4′-dihydroxy-7-methoxyisoflavone
4′-glucoside (prunetrin), isoquercitrin, catechin, epicatechin, and procyanidin B-1, B-2, B-3 and B-4, while the pale yellow
cells produced only a small amount of catechin and epicatechin as main flavonoids. These flavonoid compounds found in the
red cell culture were present also in maturePrunus leaves.
Maximum growth and maximum amount of total phenol and proanthocyanidin (procyanidins) were obtained with 0.3 mg/l of both
2,4-D and kinetin. Maximum concentration of anthocyanin was also obtained with 0.3 mg/l 2, 4-D regardless of kinetin concentration.
Accumulation of proanthocyanidin was markedly stimulated by low concentrations of phosphate, which reduced growth by about
half, and also by high concentrations of inorganic nitrogen. Production of both anthocyanin and proanthocyanidin was reduced
by lowered nitrogen levels. Cell growth and production of all phenolics were inhibited when ammonium ion replaced nitrate
in the medium. 相似文献
105.
Lubbers T de Haan JJ Hadfoune M Zabeau L Tavernier J Zhang Y Grundy D Greve JW Buurman WA 《The Journal of nutritional biochemistry》2011,22(12):1105-1111
Enteral administration of lipid-enriched nutrition effectively attenuates inflammation via a cholecystokinin (CCK)-mediated vagovagal anti-inflammatory reflex. Cholecystokinin release and subsequent activation of the vagus are dependent on chylomicron formation and associated with release of additional gut peptides. The current study investigates the intestinal processes underlying activation of the CCK-mediated vagal anti-inflammatory pathway by lipid-enriched nutrition. Rats and mice were subjected to hemorrhagic shock (HS) or endotoxemia, respectively. Prior to the experimental procedures, animals were fasted or fed lipid-enriched nutrition. Pluronic L-81 (L-81) was added to the feeding to investigate involvement of chylomicron formation in activation of mesenteric afferent fibers and the immune-modulating potential of lipid-enriched nutrition. Ob/Ob mice and selective receptor antagonists were used to study the role of leptin, glucagon-like peptide 1 and peptide YY in activation of the nutritional reflex. Electrophysiological analysis of mesenteric afferents in mice revealed that lipid-enriched nutrition-mediated neural activation was abrogated by L-81 (P<.05). L-81 blunted the beneficial effects of lipid-enriched nutrition on systemic inflammation and intestinal integrity in both species (all parameters, P<.01). Ob/Ob mice required a higher dose of nutrition compared with wild-type mice to attenuate plasma levels of TNF-α and ileum-lipid binding protein, a marker for enterocyte damage (both P<.01), suggesting a higher stimulation threshold in leptin-deficient mice. Administration of a glucagon-like peptide 1-receptor antagonist, but not leptin or peptide YY antagonists, suppressed the effects of lipid-enriched nutrition. These data indicate that chylomicron formation is essential and activation of the glucagon-like peptide 1-receptor is involved in activation of the nutritional anti-inflammatory pathway by lipid-enriched nutrition. 相似文献
106.
Membrane proteins serve crucial signaling and transport functions, yet relatively little is known about their structures in membrane environments or how lipids interact with these proteins. For voltage-activated ion channels, X-ray structures suggest that the mobile voltage-sensing S4 helix would be exposed to the membrane, and functional studies reveal that lipid modification can profoundly alter channel activity. Here, we use solid-state NMR to investigate structural interactions of lipids and water with S1-S4 voltage-sensing domains and to explore whether lipids influence the structure of the protein. Our results demonstrate that S1-S4 domains exhibit extensive interactions with lipids and that these domains are heavily hydrated when embedded in a membrane. We also find evidence for preferential interactions of anionic lipids with S1-S4 domains and that these interactions have lifetimes on the timescale of ≤ 10− 3 s. Arg residues within S1-S4 domains are well hydrated and are positioned in close proximity to lipids, exhibiting local interactions with both lipid headgroups and acyl chains. Comparative studies with a positively charged lipid lacking a phosphodiester group reveal that this lipid modification has only modest effects on the structure and hydration of S1-S4 domains. Taken together, our results demonstrate that Arg residues in S1-S4 voltage-sensing domains reside in close proximity to the hydrophobic interior of the membrane yet are well hydrated, a requirement for carrying charge and driving protein motions in response to changes in membrane voltage. 相似文献
107.
Ole Martin Moen 《Bioethics》2019,33(2):223-229
In this paper, I present and criticize Ted Kaczynski’s (“The Unabomber”) theory that industrialization has been terrible for humanity, and that we should use any means necessary, including violent means, to induce a return to pre‐industrial ways of living. Although Kaczynski’s manifesto, Industrial society and its future, has become widely known, his ideas have never before been subject to careful philosophical criticism. In this paper I show how Kaczynski’s arguments rely on a number of highly implausible philosophical premises. I further make the case that, although his theory as a whole should be rejected, Kaczynski raises a number of worries about technological development that ought to receive serious attention. Some of these worries have recently come to be shared by prominent defenders of human enhancement, including Nick Bostrom and Julian Savulescu. In the last section I indicate why I believe it is important that academic philosophers scrutinize ideas that motivate acts of violence. 相似文献
108.
The wolfberry (Lycium barbarumL.) fruit has been used in traditional Chinese medicine and food, but fruits grown in various geographic areas are significantly different in quality and content of functional components. In this study, we tested the internal nutritional ingredients and related environmental factors using forty-two wolfberry fruits collected from seven wolfberry producing regions in China (Yinchuan and Zhongning in Ningxia, Jingyuan in Gansu, Nuomuhong Farm in Qinghai,Hangjinhouqi and Wulateqianqi in Inner Mongolia, and Jinghe in Xinjiang). The nutritional ingredients of the forty-two wolfberry fruits are dependent on the environment. Correlation analysis revealed that the amount of nutrients was highly related to each other. Based on the analysis ofratio of total sugar to betaine (sugar-alkali ratio), we have successfully established quality standards for the wolfberry based on the levels of betaine and sugar. The standards were as follows: high betaine low sugar (sugar-alkali ratio≤15.1), high betaine medium sugar (15<sugar-alkali ratio≤60), medium betaine medium sugar (60<sugar-alkali ratio≤121), medium betaine high sugar (121<sugar-alkali ratio≤165), and low betaine high sugar (sugar-alkali ratio>165). Zhongning of Ningxia is the geo-authentic producing region of the wolfberry, whereby the wolfberries are rich in main pharmacological ingredients Lycium barbarum polysaccharide (LBP) and three trace elements (iron, manganese and selenium) and medium sugar-alkali ratio. In addition, the correlation analysis showed that both the altitude and average temperature difference between day and night had positive effects on the wolfberry flavonoids content but the annual sunshine duration negatively affected the betaine contents of the wolfberry fruit. 相似文献
109.
110.
Fenton A 《Developing world bioethics》2009,9(2):47-56
This paper integrates some Buddhist moral values, attitudes and self-cultivation techniques into a discussion of the ethics of cognitive enhancement technologies – in particular, pharmaceutical enhancements. Many Buddhists utilize meditation techniques that are both integral to their practice and are believed to enhance the cognitive and affective states of experienced practitioners. Additionally, Mahāyāna Buddhism's teaching on skillful means permits a liberal use of methods or techniques in Buddhist practice that yield insight into our selfnature or aid in alleviating or eliminating du kha (i.e. dissatisfaction). These features of many, if not most, Buddhist traditions will inform much of the Buddhist assessment of pharmaceutical enhancements offered in this paper. Some Buddhist concerns about the effects and context of the use of pharmaceutical enhancements will be canvassed in the discussion. Also, the author will consider Buddhist views of the possible harms that may befall human and nonhuman research subjects, interference with a recipient's karma , the artificiality of pharmaceutical enhancements, and the possible motivations or intentions of healthy individuals pursuing pharmacological enhancement. Perhaps surprisingly, none of these concerns will adequately ground a reflective Buddhist opposition to the further development and continued use of pharmaceutical enhancements, either in principle or in practice. The author argues that Buddhists, from at least certain traditions – particularly Mahāyāna Buddhist traditions – should advocate the development or use of pharmaceutical enhancements if a consequence of their use is further insight into our self-nature or the reduction or alleviation of du kha . 相似文献