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21.
Vincent Grossi Damien Mollex Arnauld Vin?on-Laugier Florence Hakil Muriel Pacton Cristiana Cravo-Laureau 《Applied and environmental microbiology》2015,81(9):3157-3168
Bacterial glycerol ether lipids (alkylglycerols) have received increasing attention during the last decades, notably due to their potential role in cell resistance or adaptation to adverse environmental conditions. Major uncertainties remain, however, regarding the origin, biosynthesis, and modes of formation of these uncommon bacterial lipids. We report here the preponderance of monoalkyl- and dialkylglycerols (1-O-alkyl-, 2-O-alkyl-, and 1,2-O-dialkylglycerols) among the hydrolyzed lipids of the marine mesophilic sulfate-reducing proteobacterium Desulfatibacillum alkenivorans PF2803T grown on n-alkenes (pentadec-1-ene or hexadec-1-ene) as the sole carbon and energy source. Alkylglycerols account for one-third to two-thirds of the total cellular lipids (alkylglycerols plus acylglycerols), depending on the growth substrate, with dialkylglycerols contributing to one-fifth to two-fifths of the total ether lipids. The carbon chain distribution of the lipids of D. alkenivorans also depends on that of the substrate, but the chain length and methyl-branching patterns of fatty acids and monoalkyl- and dialkylglycerols are systematically congruent, supporting the idea of a biosynthetic link between the three classes of compounds. Vinyl ethers (1-alken-1′-yl-glycerols, known as plasmalogens) are not detected among the lipids of strain PF2803T. Cultures grown on different (per)deuterated n-alkene, n-alkanol, and n-fatty acid substrates further demonstrate that saturated alkylglycerols are not formed via the reduction of hypothetic alken-1′-yl intermediates. Our results support an unprecedented biosynthetic pathway to monoalkyl/monoacyl- and dialkylglycerols in anaerobic bacteria and suggest that n-alkyl compounds present in the environment can serve as the substrates for supplying the building blocks of ether phospholipids of heterotrophic bacteria. 相似文献
22.
Tiffany M. Mott Sudhamathi Vijayakumar Elena Sbrana Janice J. Endsley Alfredo G. Torres 《PLoS neglected tropical diseases》2015,9(6)
BackgroundIn this study, a Burkholderia mallei tonB mutant (TMM001) deficient in iron acquisition was constructed, characterized, and evaluated for its protective properties in acute inhalational infection models of murine glanders and melioidosis.Conclusions/SignificanceAlthough further work is needed to prevent chronic infection by TMM001 while maintaining immunogenicity, our attenuated strain demonstrates great potential as a backbone strain for future vaccine development against both glanders and melioidosis. 相似文献
23.
Cristiana Pistol Tanase Simona Dima Mihaela Mihai Elena Raducan Mihnea Ioan Nicolescu Lucian Albulescu Bogdan Voiculescu Traian Dumitrascu Linda Maria Cruceru Mircea Leabu Irinel Popescu Mihail Eugen Hinescu 《Journal of molecular histology》2009,40(1):23-29
The assessment of caveolin-1 (Cav-1) as a marker of tumor aggressiveness in pancreatic ductal adenocarcinoma (PDAC). In this
study, we examined the expression of Cav-1 in 34 human PDAC tissue samples and the associated peritumoral tissues by immunohistochemistry
and western blot. Additionally, we correlated Cav-1 expression with other tissue (Ki-67, p53) and serum (CA 19-9) tumor markers.
In the tumor-derived tissue, both tumor cells and blood vessels expressed Cav-1. In contrast, in peritumoral tissue, Cav-1
expression was confined mainly to blood vessels and was only occasionally expressed in ductal or parenchymal cells. Western
blot analysis confirmed the overexpression of Cav-1 in pancreatic tumors compared with peritumoral tissue. Cav-1 expression
in tumor tissues was correlated with both the Ki-67 LI (r = 0.95, P < 0.0001) and p53 expression (χ2 = 9.91, P < 0.005). Overexpression of Cav-1 was associated with tumor size, grade and stage and Cav-1 expression in tumors was correlated
with an increased serum level of CA 19-9 (r = 0.795, P < 0.001). Based on the results of this study, the inclusion of Cav-1 in a putative panel of biomarkers predicting pancreatic
cancer aggressiveness is warranted. 相似文献
24.
Joana Martins Martin L. Saker Cristiana Moreira Martin Welker Jutta Fastner Vitor M. Vasconcelos 《Applied microbiology and biotechnology》2009,82(5):951-961
Strains of the cyanobacterium Microcystis aeruginosa were isolated into pure culture from a variety of lakes, rivers, and reservoirs in Portugal. Samples were tested with matrix-assisted
laser desorption/ionization–time-of-flight mass spectrometry (MALDI-TOF MS) to investigate the presence of various peptide
groups including aeruginosins, microginins, anabaenopeptins, cyanopeptilins, microcystins, and microviridins and other peptide-like
compounds. Binary data, based on the presence and absence of different peptide groups, were analyzed by phylogenetic inference.
DNA was also extracted from the samples and tested using a range of primers. Those strains that gave positive results for
a Microcystis-specific primer pair were further analyzed for the presence of genes linked to the biosynthesis of microginin and microcystin.
The results showed that a wide range of microcystin forms were produced by the strains among which MC-LR, -FR, -RR, -WR, and
-YR were the most common. The peptide profiles obtained from the MALDI analysis were assessed using cluster analysis which
resulted in the formation of distinct groups or chemotypes. 相似文献
25.
26.
The aim of this study is to provide information on the fishing pattern of Parapenaeus longirostris in the northern Tyrrhenian Sea (western Mediterranean), in order to improve the management of the resource in the area. Data
were obtained from commercial fishery, covering the period 1991–2002. Catch rates revealed notable inter-annual fluctuation
of the P. longirostris landing, probably due to the life cycle of the species. The highest yields (kg per hour of trawl) of the commercial fishery
were obtained at depths ranging between 180 and 300 m, the lower ones at depths between 100 and 180 m, where small specimens
are more abundant. Commercial catches were characterised by a very low presence of specimens smaller than 20 mm carapace length
(CL), mainly due to the deeper localisation of the fishing grounds when compared to the recruitment areas of the species.
The size at which 50% of the specimens were discarded by the fishermen was 15 mm CL, while the estimated size at first capture
of the individuals caught by the commercial net was 12.4 mm CL. 相似文献
27.
Luís Abrunhosa Felisbela Oliveira Danielle Dantas Cristiana Gonçalves Isabel Belo 《Bioprocess and biosystems engineering》2013,36(3):285-291
Olive mill wastewater (OMW) characteristics make it a suitable resource to be used as a microbial culture media to produce value-added compounds, such as enzymes. In this work, the ability of the novel species Aspergillus ibericus to discolor OMW and produce lipase was studied. An initial screening on plates containing an OMW-based agar medium and an emulsified olive oil/rhodamine-B agar medium was employed to select the strain A. ibericus MUM 03.49. Then, experiments in conical flasks with liquid OMW-based media showed that the fungus could growth on undiluted OMW, with a chemical oxygen demand (COD) of 97 ± 2 g/L, and to produce up to 2,927 ± 54 U/L of lipase. When pure OMW was used in the media, the maximum COD and color reduction achieved were 45 and 97 %, respectively. When OMW diluted to 10 % was used, A. ibericus was able to reduce phenolic and aromatic compounds by 37 and 39 %, respectively. Additionally, lipase production was found to be promoted by the addition of mineral nutrients. When the fermentations were scaled up to a 2-L bioreactor, A. ibericus produced up to 8,319 ± 33 U/L of lipase, and the maximum COD and color reduction were 57 and 24 %, respectively. 相似文献
28.
Valeria Rimoldi Giulia Soldà Rosanna Asselta Silvia Spena Cristiana Stuani Emanuele Buratti Stefano Duga 《PloS one》2013,8(3)
Most pathological pseudoexon inclusion events originate from single activating mutations, suggesting that many intronic sequences are on the verge of becoming exons. However, the precise mechanisms controlling pseudoexon definition are still largely unexplored. Here, we investigated the cis-acting elements and trans-acting regulatory factors contributing to the regulation of a previously described fibrinogen gamma-chain (FGG) pseudoexon, which is activated by a deep-intronic mutation (IVS6-320A>T). This pseudoexon contains several G-run elements, which may be bound by heterogeneous nuclear ribonucleoproteins (hnRNPs) F and H. To explore the effect of these proteins on FGG pseudoexon inclusion, both silencing and overexpression experiments were performed in eukaryotic cells. While hnRNP H did not significantly affect pseudoexon splicing, hnRNP F promoted pseudoexon inclusion, indicating that these two proteins have only partially redundant functions. To verify the binding of hnRNP F and the possible involvement of other trans-acting splicing modulators, pulldown experiments were performed on the region of the pseudoexon characterized by both a G-run and enrichment for exonic splicing enhancers. This 25-bp-long region strongly binds hnRNP F/H and weakly interacts with Serine/Arginine-rich protein 40, which however was demonstrated to be dispensable for FGG pseudoexon inclusion in overexpression experiments. Deletion analysis, besides confirming the splicing-promoting role of the G-run within this 25-bp region, demonstrated that two additional hnRNP F binding sites might instead function as silencer elements. Taken together, our results indicate a major role of hnRNP F in regulating FGG pseudoexon inclusion, and strengthen the notion that G-runs may function either as splicing enhancers or silencers of the same exon. 相似文献
29.
Paola Luciani Cristiana Deledda Susanna Benvenuti Roberta Squecco Ilaria Cellai Benedetta Fibbi Ilaria Maddalena Marone Corinna Giuliani Giulia Modi Fabio Francini Gabriella Barbara Vannelli Alessandro Peri 《PloS one》2013,8(8)
Exendin-4 is a molecule currently used, in its synthetic form exenatide, for the treatment of type 2 diabetes mellitus. Exendin-4 binds and activates the Glucagon-Like Peptide-1 Receptor (GLP-1R), thus inducing insulin release. More recently, additional biological properties have been associated to molecules that belong to the GLP-1 family. For instance, Peptide YY and Vasoactive Intestinal Peptide have been found to affect cell adhesion and migration and our previous data have shown a considerable actin cytoskeleton rearrangement after exendin-4 treatment. However, no data are currently available on the effects of exendin-4 on tumor cell motility. The aim of this study was to investigate the effects of this molecule on cell adhesion, differentiation and migration in two neuroblastoma cell lines, SH-SY5Y and SK-N-AS. We first demonstrated, by Extra Cellular Matrix cell adhesion arrays, that exendin-4 increased cell adhesion, in particular on a vitronectin substrate. Subsequently, we found that this molecule induced a more differentiated phenotype, as assessed by i) the evaluation of neurite-like protrusions in 3D cell cultures, ii) the analysis of the expression of neuronal markers and iii) electrophysiological studies. Furthermore, we demonstrated that exendin-4 reduced cell migration and counteracted anchorage-independent growth in neuroblastoma cells. Overall, these data indicate for the first time that exendin-4 may have anti-tumoral properties. 相似文献
30.
Gloria Taliani Martina Spaziante Elisa Biliotti Marina Borro Donatella Palazzo Stefania Grieco Cristiana Franchi Giancarlo Iaiani Caterina Furlan Valentina Gallinaro Maurizio Simmaco 《PloS one》2013,8(8)