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51.
Tomasz B. Owczarek Jaros?aw Suchanski Bartosz Pula Alicja M. Kmiecik Marek Chadalski Aleksandra Jethon Piotr Dziegiel Maciej Ugorski 《PloS one》2013,8(12)
It was recently proposed that UDP-galactose:ceramide galactosyltransferase (UGT8), enzyme responsible for synthesis of galactosylceramide (GalCer), is a significant index of tumor aggressiveness and a potential marker for the prognostic evaluation of lung metastases in breast cancer. To further reveal the role of UGT8 and GalCer in breast cancer progression, tumorigenicity and metastatic potential of control MDA-MB-231 cells (MDA/LUC) and MDA-MB-231 cells (MDA/LUC-shUGT8) with highly decreased expression of UGT8 and GalCer after stable expression of shRNA directed against UGT8 mRNA was studied in vivo in athymic nu/nu mice. Control MDA/LUC cells formed tumors and metastatic colonies much more efficiently in comparison to MDA/LUC-shUGT8 cells with suppressed synthesis of GalCer after their, respectively, orthotopic and intracardiac transplantation. These findings indicate that UGT8 and GalCer have a profound effect on tumorigenic and metastatic properties of breast cancer cells. In accordance with this finding, immunohistochemical staining of tumor specimens revealed that high expression of UGT8 accompanied by accumulation of GalCer in MDA-MB-231 cells is associated with a much higher proliferative index and a lower number of apoptotic cells in comparison to the MDA/LUC-shUGT8 cells. In addition, it was found that expression of UGT8 in MDA-MB-231 cells increased their resistance to apoptosis induced by doxorubicin in vitro. Therefore, these data suggest that accumulation of GalCer in tumor cells inhibits apoptosis, which would facilitates metastatic cells to survive in the hostile microenvironment of tumor in target organ. 相似文献
52.
The electronic spectrum of four different anthraquinones (1,2-dihydroxyanthraquinone, 1-aminoanthraquinone, 2-aminoanthraquinone and 1-amino-2-methylanthraquinone) in methanol solution was measured and used as reference data for theoretical color prediction. The visible part of the spectrum was modeled according to TD-DFT framework with a broad range of DFT functionals. The convoluted theoretical spectra were validated against experimental data by a direct color comparison in terms of CIE XYZ and CIE Lab tristimulus model color. It was found, that the 6-31G** basis set provides the most accurate color prediction and there is no need to extend the basis set since it does not improve the prediction of color. Although different functionals were found to give the most accurate color prediction for different anthraquinones, it is possible to apply the same DFT approach for the whole set of analyzed dyes. Especially three functionals seem to be valuable, namely mPW1LYP, B1LYP and PBE0 due to very similar spectra predictions. The major source of discrepancies between theoretical and experimental spectra comes from L values, representing the lightness, and the a parameter, depicting the position on green→magenta axis. Fortunately, the agreement between computed and observed blue→yellow axis (parameter b) is very precise in the case of studied anthraquinone dyes in methanol solution. Despite discussed shortcomings, color prediction from first principle quantum chemistry computations can lead to quite satisfactory results, expressed in terms of color space parameters. 相似文献
53.
Barbara Stopa Anna Jagusiak Leszek Konieczny Barbara Piekarska Janina Rybarska Grzegorz Zemanek Marcin Król Piotr Piwowar Irena Roterman 《Journal of molecular modeling》2013,19(11):4731-4740
Congo red dye as well as other eagerly self-assembling organic molecules which form rod-like or ribbon-like supramolecular structures in water solutions, appears to represent a new class of protein ligands with possible wide-ranging medical applications. Such molecules associate with proteins as integral clusters and preferentially penetrate into areas of low molecular stability. Abnormal, partly unfolded proteins are the main binding target for such ligands, while well packed molecules are generally inaccessible. Of particular interest is the observation that local susceptibility for binding supramolecular ligands may be promoted in some proteins as a consequence of function-derived structural changes, and that such complexation may alter the activity profile of target proteins. Examples are presented in this paper. 相似文献
54.
The biospeckle phenomenon is used for non-destructive monitoring the quality of fresh fruits and vegetables, but in the case of plant tissues there is a lack of experimentally confirmed information about the biological origin of the biospeckle activity (BA). As a main sources of BA, processes associated with the movement inside the cell, such as cytoplasmic streaming, organelle movement and intra- and extracellular transport mechanisms, are considered. The aim of this study is to investigate the effect of metabolism inhibitors, connected with intracellular movement such as cytochalasin B, lantrunculin B, colchicine, cycloheximid, dimethyl sulfoxide (DMSO) and mixture of ion channel inhibitors, injected into apples, on BA. Two methods of BA analysis based on cross-correlation coefficient and Laser Speckle Contrast Analysis (LASCA) were used. DMSO, lantrunculin B and mixture of ion channel inhibitors have a significant effect on BA, and approximately 74 % of BA of apple tissue is potentially caused by biological processes. Results indicate that the functioning of actin microfilaments and ion channels significantly affect BA. 相似文献
55.
Natalie Saini Yu Zhang Yuri Nishida Ziwei Sheng Shilpa Choudhury Piotr Mieczkowski Kirill S. Lobachev 《PLoS genetics》2013,9(6)
DNA sequences capable of adopting non-canonical secondary structures have been associated with gross-chromosomal rearrangements in humans and model organisms. Previously, we have shown that long inverted repeats that form hairpin and cruciform structures and triplex-forming GAA/TTC repeats induce the formation of double-strand breaks which trigger genome instability in yeast. In this study, we demonstrate that breakage at both inverted repeats and GAA/TTC repeats is augmented by defects in DNA replication. Increased fragility is associated with increased mutation levels in the reporter genes located as far as 8 kb from both sides of the repeats. The increase in mutations was dependent on the presence of inverted or GAA/TTC repeats and activity of the translesion polymerase Polζ. Mutagenesis induced by inverted repeats also required Sae2 which opens hairpin-capped breaks and initiates end resection. The amount of breakage at the repeats is an important determinant of mutations as a perfect palindromic sequence with inherently increased fragility was also found to elevate mutation rates even in replication-proficient strains. We hypothesize that the underlying mechanism for mutagenesis induced by fragile motifs involves the formation of long single-stranded regions in the broken chromosome, invasion of the undamaged sister chromatid for repair, and faulty DNA synthesis employing Polζ. These data demonstrate that repeat-mediated breaks pose a dual threat to eukaryotic genome integrity by inducing chromosomal aberrations as well as mutations in flanking genes. 相似文献
56.
Piotr Sorokowski Agnieszka Sorokowska Dariusz P. Danel 《Economics & Human Biology》2013,11(3):382-390
Many studies have investigated how different variables influence the reproductive success (RS) in the populations of natural birth control. Here, we tested hypotheses about positive relationship between wealth, height and several measures of RS in an indigenous, traditional society from West Papua. The study was conducted among the Yali tribe in a few small, isolated mountain villages. In this tribe, a man's wealth is measured by the number of pigs he possesses. We found that wealth was related to fertility and number of living children, but not to child mortality in both men and women. Additionally, child mortality increased with the number of children in a family. Finally, we did not observe any relationship between height and reproductive success measures or wealth. We provide several possible explanations of our results and also put forward hypothetical background for further studies of indigenous populations. 相似文献
57.
Anna Wojakowska Dorota Muth Dorota Narożna Cezary Mądrzak Maciej Stobiecki Piotr Kachlicki 《Metabolomics : Official journal of the Metabolomic Society》2013,9(3):575-589
Plant interactions with environmental factors cause changes in the metabolism and regulation of biochemical and physiological processes. Plant defense against pathogenic microorganisms depends on an innate immunity system that is activated as a result of infection. There are two mechanisms of triggering this system: basal immunity activated as a result of a perception of microbe-associated molecular patterns through pattern recognition receptors situated on the cell surface and effector-triggered immunity (ETI). An induced biosynthesis of bioactive secondary metabolites, in particular phytoalexins, is one of the mechanisms of plant defense to fungal infection. Results of the study on narrow leaf lupin (Lupinus angustifolius L.) plants infected with the anthracnose fungus Colletotrichum lupini and treated with fungal phytotoxic metabolites are described in the paper. The C. lupini phytotoxins were isolated from liquid cultures, purified and partially characterized with physicochemical methods. Accumulation of secondary metabolites on leaf surface and within the tissues of plants either infected, treated with the fungal phytotoxin or submitted to both treatments was studied using GC-MS and LC-MS, respectively. Substantial differences in isoflavone aglycones and glycoconjugate profiles occurred in response to different ways of plant treatment. 相似文献
58.
Andrzej Matyja Krzysztof Gil Artur Pasternak Krystyna Sztefko Mariusz Gajda Krzysztof A. Tomaszewski Maciej Matyja Jerzy A. Walocha Jan Kulig Piotr Thor 《Journal of cellular and molecular medicine》2013,17(6):734-742
The major mechanisms of gallstone formation include biliary cholesterol hypersecretion, supersaturation and crystallization, mucus hypersecretion, gel formation and bile stasis. Gallbladder hypomotility seems to be a key event that triggers the precipitation of cholesterol microcrystals from supersaturated lithogenic bile. Telocytes, a new type of interstitial cells, have been recently identified in many organs, including gallbladder. Considering telocyte functions, it is presumed that these cells might be involved in the signalling processes. The purpose of this study was to correlate the quantity of telocytes in the gallbladder with the lithogenicity of bile. Gallbladder specimens were collected from 24 patients who underwent elective laparoscopic cholecystectomy for symptomatic gallstone disease. The control group consisted of 25 consecutive patients who received elective treatment for pancreatic head tumours. Telocytes were visualized in paraffin sections of gallbladders with double immunofluorescence using primary antibodies against c‐Kit (anti‐CD117) and anti‐mast cell tryptase. Cholesterol, phospholipid and bile acid levels were measured in gallbladder bile. The number of telocytes in the gallbladder wall was significantly lower in the study group than that in the control group (3.03 ± 1.43 versus 6.34 ± 1.66 cell/field of view in the muscularis propria, P < 0.001) and correlated with a significant increase in the cholesterol saturation index. The glycocholic and taurocholic acid levels were significantly elevated in the control subjects compared with the study group. The results suggest that bile composition may play an important role in the reduction in telocytes density in the gallbladder. 相似文献
59.
Piotr Wysoczanski Robert J. Mart E. Joel Loveridge Christopher Williams Sara B.-M. Whittaker Matthew P. Crump Rudolf K. Allemann 《Biomolecular NMR assignments》2013,7(2):187-191
Here we report the 1H, 13C and 15N resonance assignments of free Bcl-xL and of Bcl-xL in complex with an azobenzene-modified peptide derived from the BH3 domain of the pro-apoptotic Bak. The spectra suggest predominantly folded proteins; chemical shift difference analysis provides a detailed view of the reorganization occurring on peptide binding. 相似文献
60.
Izabela Chojnicka Krzysztof Gajos Katarzyna Strawa Gra?yna Broda Sylwia Fudalej Marcin Fudalej Piotr Stawiński Aleksandra Pawlak Pawe? Krajewski Marcin Wojnar Rafa? P?oski 《PloS one》2013,8(2)