521 research outputs found

    The Active Component of Aspirin, Salicylic Acid, Promotes Staphylococcus aureus Biofilm Formation in a PIA-dependent Manner

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    Aspirin has provided clear benefits to human health. But salicylic acid (SAL) -the main aspirin biometabolite- exerts several effects on eukaryote and prokaryote cells. SAL can affect, for instance, the expression of Staphyiococcus aureus virulence factors. SAL can also form complexes with iron cations and it has been shown that different iron chelating molecules diminished the formation of S. aureus biofilm. The aim of this study was to elucidate whether the iron content limitation caused by SAL can modify the S. aureus metabolism and/or metabolic regulators thus changing the expression of the main polysaccharides involved in biofilm formation. The exposure of biofilm to 2mM SAL induced a 27% reduction in the intracellular free Fe2+ concentration compared with the controls. In addition, SAL depleted 23% of the available free Fe2+ cation in culture media. These moderate iron-limited conditions promoted an intensificaron of biofilms formed by strain Newman and by S. aureus clinical isolates related to the USA300 and USA100 clones. The slight decrease in iron bioavailability generated by SAL was enough to induce the increase of PIA expression in biofilms formed by methicillin-resistant as well as methicillin-sensitive S. aureus strains. S. aureus did not produce capsular polysaccharide (CP) when it was forming biofilms under any of the experimental conditions tested. Furthermore, SAL diminished aconitase activity and stimulated the lactic fermentation pathway in bacteria forming biofilms. The polysaccharide composition of S. aureus biofilms was examined and FTIR spectroscopic analysis revealed a clear impact of SAL in a codY-dependent manner. Moreover, SAL negatively affected codY transcription in mature biofilms thus relieving the CodY repression of the ica operon. Treatment of mice with SAL induced a significant increase of S aureus colonization. It is suggested that the elevated PIA expression induced by SAL might be responsible for the high nasal colonization observed in mice. SAL-induced biofilms may contribute to S. aureus infection persistence in vegetarian individuals as well as in patients that frequently consume aspirin.Facultad de Ciencias Médica

    Effect of exposing rams to a female stimulus before semen collection on ram libido and semen quality

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    peer-reviewedRams with strong libido and desirable semen characteristics can provide more insemination doses per ejaculate and produce more progeny, improving population genetic linkage to improve the accuracy of EBV. The objective of this study was to determine if teasing rams, either by sight and smell alone (Exp. 1), or physical contact (Exp. 2), could improve libido and semen quality of rams. In Exp. 1, there were 3 treatments in which rams were exposed to the sight and smell of the ewe for 1 h: control treatment (n = 5) in which rams were exposed to a ewe not in estrus; non-novel treatment (n = 6) in which rams were exposed to a ewe in estrus and the same ewe was used for semen collection; and novel treatment (n = 6) in which rams were exposed to a ewe in estrus and a different ewe in estrus was used for semen collection. In Exp. 2, rams were individually given full access to a ewe, which had a cotton apron fi tted to cover her vulva, for 15 min. The 3 treatments in Exp. 2 were: control treatment (n = 5) in which rams were placed in a pen with a ewe not in estrus; a nonnovel treatment (n = 5) in which rams were placed in a pen with a ewe in estrus and the same ewe was used for semen collection; novel treatment (n = 6) in which rams were placed in a pen with a ewe in estrus and a different ewe in estrus was used for semen collection. Experiment 1 was repeated for 5 consecutive days and Exp. 2 was repeated for 4 consecutive days. Data on reaction time, number of mounts, semen volume, semen concentration, sperm wave motion, and progressive linear motion (Exp. 1 only) were collected and analyzed as a randomized complete block design, where rams were initially blocked for breed and age. In Exp. 1, there was an effect of day (P < 0.05) and a treatment × day interaction (P < 0.05) on semen volume, whereas there was also an effect of treatment (P < 0.05) and day (P < 0.01) on semen concentration, which was most evident on d 1. In Exp. 2, there was an effect of treatment on reaction time (P < 0.05) and semen volume (P = 0.08), which was most evident on d 1. This study demonstrates an acute effect on d 1 on semen concentration when rams were exposed to the sight and smell of a ewe in estrus. Alternatively, when rams were stimulated with physical contact of a ewe in estrus, an acute increase in semen volume was evident on d 1. These effects were not evident on subsequent days and thus the overall benefi ts on ram libido and semen quality of exposing rams to ewes in estrus are minimal.PUBLISHEDpeer-reviewe

    Glufosinate constrains synchronous and metachronous metastasis by promoting anti-tumor macrophages

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    Abstract Glutamine synthetase (GS) generates glutamine from glutamate and controls the release of inflammatory mediators. In macrophages, GS activity, driven by IL10, associates to the acquisition of M2‐like functions. Conditional deletion of GS in macrophages inhibits metastasis by boosting the formation of anti‐tumor, M1‐like, tumor‐associated macrophages (TAMs). From this basis, we evaluated the pharmacological potential of GS inhibitors in targeting metastasis, identifying glufosinate as a specific human GS inhibitor. Glufosinate was tested in both cultured macrophages and on mice bearing metastatic lung, skin and breast cancer. We found that glufosinate rewires macrophages toward an M1‐like phenotype both at the primary tumor and metastatic site, countering immunosuppression and promoting vessel sprouting. This was also accompanied to a reduction in cancer cell intravasation and extravasation, leading to synchronous and metachronous metastasis growth inhibition, but no effects on primary tumor growth. Glufosinate treatment was well‐tolerated, without liver and brain toxicity, nor hematopoietic defects. These results identify GS as a druggable enzyme to rewire macrophage functions and highlight the potential of targeting metabolic checkpoints in macrophages to treat cancer metastasis

    ITIH5 mediates epigenetic reprogramming of breast cancer cells

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    Extracellular matrix (ECM) is known to maintain epithelial integrity. In carcinogenesis ECM degradation triggers metastasis by controlling migration and differentiation including cancer stem cell (CSC) characteristics. The ECM-modulator inter- α-trypsin inhibitor heavy chain family member five (ITIH5) was recently identified as tumor suppressor potentially involved in impairing breast cancer progression but molecular mechanisms underlying its function are still elusive

    The Active Component of Aspirin, Salicylic Acid, Promotes Staphylococcus aureus Biofilm Formation in a PIA-dependent Manner

    Get PDF
    Aspirin has provided clear benefits to human health. But salicylic acid (SAL) -the main aspirin biometabolite- exerts several effects on eukaryote and prokaryote cells. SAL can affect, for instance, the expression of Staphyiococcus aureus virulence factors. SAL can also form complexes with iron cations and it has been shown that different iron chelating molecules diminished the formation of S. aureus biofilm. The aim of this study was to elucidate whether the iron content limitation caused by SAL can modify the S. aureus metabolism and/or metabolic regulators thus changing the expression of the main polysaccharides involved in biofilm formation. The exposure of biofilm to 2mM SAL induced a 27% reduction in the intracellular free Fe2+ concentration compared with the controls. In addition, SAL depleted 23% of the available free Fe2+ cation in culture media. These moderate iron-limited conditions promoted an intensificaron of biofilms formed by strain Newman and by S. aureus clinical isolates related to the USA300 and USA100 clones. The slight decrease in iron bioavailability generated by SAL was enough to induce the increase of PIA expression in biofilms formed by methicillin-resistant as well as methicillin-sensitive S. aureus strains. S. aureus did not produce capsular polysaccharide (CP) when it was forming biofilms under any of the experimental conditions tested. Furthermore, SAL diminished aconitase activity and stimulated the lactic fermentation pathway in bacteria forming biofilms. The polysaccharide composition of S. aureus biofilms was examined and FTIR spectroscopic analysis revealed a clear impact of SAL in a codY-dependent manner. Moreover, SAL negatively affected codY transcription in mature biofilms thus relieving the CodY repression of the ica operon. Treatment of mice with SAL induced a significant increase of S aureus colonization. It is suggested that the elevated PIA expression induced by SAL might be responsible for the high nasal colonization observed in mice. SAL-induced biofilms may contribute to S. aureus infection persistence in vegetarian individuals as well as in patients that frequently consume aspirin.Facultad de Ciencias Médica

    Cerebrospinal Fluid B Cells Correlate with Early Brain Inflammation in Multiple Sclerosis

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    Background: There is accumulating evidence from immunological, pathological and therapeutic studies that B cells are key components in the pathophysiology of multiple sclerosis (MS). Methodology/Principal Findings: In this prospective study we have for the first time investigated the differences in the inflammatory response between relapsing and progressive MS by comparing cerebrospinal fluid (CSF) cell profiles from patients at the onset of the disease (clinically isolated syndrome, CIS), relapsing-remitting (RR) and chronic progressive (CP) MS by flow cytometry. As controls we have used patients with other neurological diseases. We have found a statistically significant accumulation of CSF mature B cells (CD19+CD1382) and plasma blasts (CD19+CD138+) in CIS and RRMS. Both B cell populations were, however, not significantly increased in CPMS. Further, this accumulation of B cells correlated with acute brain inflammation measured by magnetic resonance imaging and with inflammatory CSF parameters such as the number of CSF leukocytes, intrathecal immunoglobulin M and G synthesis and intrathecal production of matri

    Real Wage Responsiveness to Unemployment in Spain: Asymmetries Along the Business Cycle

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    We estimate real wage cyclicality in the period compressed between 1987 and 2013 using a large administrative dataset of workers in Spain. Real wages are weakly procyclical in Spain and focusing on differences in different phases of the business cycle, we find that differences across expansions and recessions are significant, with an even lower real wage cyclicality in recessions. Furthermore, higher levels of unemployment do not translate into additional real wages adjustments when the economy is contracting, while lower levels of unemployment during expansions have incremental effects on wage elasticity. This general result holds after accounting for differences in tenure, type of contract and age categories. Nevertheless, wages of newly-hired workers are the most sensitive to the business cycle and exhibit the lowest asymmetric pattern between expansions and recessions. At the other end, wages of workers with more than six years of tenure can be characterized as the most protected against economic downturns. The same is true for fixed-term vs. permanent workers, as well as for young vs. older workers

    Small intestinal mucosa expression of putative chaperone fls485

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    <p>Abstract</p> <p>Background</p> <p>Maturation of enterocytes along the small intestinal crypt-villus axis is associated with significant changes in gene expression profiles. <it>fls485 </it>coding a putative chaperone protein has been recently suggested as a gene involved in this process. The aim of the present study was to analyze <it>fls48</it>5 expression in human small intestinal mucosa.</p> <p>Methods</p> <p><it>fls485 </it>expression in purified normal or intestinal mucosa affected with celiac disease was investigated with a molecular approach including qRT-PCR, Western blotting, and expression strategies. Molecular data were corroborated with several <it>in situ </it>techniques and usage of newly synthesized mouse monoclonal antibodies.</p> <p>Results</p> <p>fls485 mRNA expression was preferentially found in enterocytes and chromaffine cells of human intestinal mucosa as well as in several cell lines including Rko, Lovo, and CaCo2 cells. Western blot analysis with our new anti-fls485 antibodies revealed at least two fls485 proteins. In a functional CaCo2 model, an increase in fls485 expression was paralleled by cellular maturation stage. Immunohistochemistry demonstrated fls485 as a cytosolic protein with a slightly increasing expression gradient along the crypt-villus axis which was impaired in celiac disease Marsh IIIa-c.</p> <p>Conclusions</p> <p>Expression and synthesis of fls485 are found in surface lining epithelia of normal human intestinal mucosa and deriving epithelial cell lines. An interdependence of enterocyte differentiation along the crypt-villus axis and fls485 chaperone activity might be possible.</p

    Comparative Transcriptional Profiling of Bacillus cereus Sensu Lato Strains during Growth in CO2-Bicarbonate and Aerobic Atmospheres

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    Bacillus species are spore-forming bacteria that are ubiquitous in the environment and display a range of virulent and avirulent phenotypes. This range is particularly evident in the Bacillus cereus sensu lato group; where closely related strains cause anthrax, food-borne illnesses, and pneumonia, but can also be non-pathogenic. Although much of this phenotypic range can be attributed to the presence or absence of a few key virulence factors, there are other virulence-associated loci that are conserved throughout the B. cereus group, and we hypothesized that these genes may be regulated differently in pathogenic and non-pathogenic strains.Here we report transcriptional profiles of three closely related but phenotypically unique members of the Bacillus cereus group--a pneumonia-causing B. cereus strain (G9241), an attenuated strain of B. anthracis (Sterne 34F(2)), and an avirulent B. cereus strain (10987)--during exponential growth in two distinct atmospheric environments: 14% CO(2)/bicarbonate and ambient air. We show that the disease-causing Bacillus strains undergo more distinctive transcriptional changes between the two environments, and that the expression of plasmid-encoded virulence genes was increased exclusively in the CO(2) environment. We observed a core of conserved metabolic genes that were differentially expressed in all three strains in both conditions. Additionally, the expression profiles of putative virulence genes in G9241 suggest that this strain, unlike Bacillus anthracis, may regulate gene expression with both PlcR and AtxA transcriptional regulators, each acting in a different environment.We have shown that homologous and even identical genes within the genomes of three closely related members of the B. cereus sensu lato group are in some instances regulated very differently, and that these differences can have important implications for virulence. This study provides insights into the evolution of the B. cereus group, and highlights the importance of looking beyond differences in gene content in comparative genomics studies
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