174 research outputs found

    A transgenic pig model expressing a CMV-ZsGreen1 reporter across an extensive array of tissues.

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    Since genetic engineering of pigs can benefit both biomedicine and agriculture, selecting a suitable gene promoter is critically important. The cytomegalovirus (CMV) promoter, which can robustly drive ubiquitous transgene expression, is commonly used at present, yet recent reports suggest tissue-specific activity in the pig. The objective of this study was to quantify ZsGreen1 protein (in lieu of CMV promoter activity) in tissues from pigs harboring a CMV-ZsGreen1 transgene with a single integration site. Tissue samples

    Endothelial and cardiomyocyte PI3KĪ² divergently regulate cardiac remodelling in response to ischaemic injury

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    AIMS: Cardiac remodeling in the ischemic heart determines prognosis in patients with ischemic heart disease (IHD), while enhancement of angiogenesis and cell survival has shown great potential for IHD despite translational challenges. Phosphoinositide 3-kinase (PI3K)/Akt signaling pathway plays a critical role in promoting angiogenesis and cell survival. However, the effect of PI3KĪ² in the ischemic heart is poorly understood. This study investigates the role of endothelial and cardiomyocyte PI3KĪ² in post-infarct cardiac remodeling. METHODS AND RESEARCH: PI3KĪ² catalytic subunit-p110Ī² level was increased in infarcted murine and human hearts. Using cell type-specific loss-of-function approaches, we reported novel and distinct actions of p110Ī² in endothelial cells versus cardiomyocytes in response to myocardial ischemic injury. Inactivation of endothelial p110Ī² resulted in marked resistance to infarction and adverse cardiac remodeling with decreased mortality, improved systolic function, preserved microvasculature, and enhanced Akt activation. Cultured endothelial cells with p110Ī² knockout or inhibition displayed preferential PI3KĪ±/Akt/eNOS signaling that consequently promoted protective signaling and angiogenesis. In contrast, mice with cardiomyocyte p110Ī²-deficiency exhibited adverse post-infarct ventricular remodeling with larger infarct size and deteriorated cardiac function, which was due to enhanced susceptibility of cardiomyocytes to ischemia-mediated cell death. Disruption of cardiomyocyte p110Ī² signaling compromised nuclear p110Ī² and phospho-Akt levels leading to perturbed gene expression and elevated pro-cell death protein levels, increasing the susceptibility to cardiomyocyte death. A similar divergent response of PI3KĪ² endothelial and cardiomyocyte mutant mice was seen using a model of myocardial ischemia-reperfusion injury. CONCLUSIONS: These data demonstrate novel, differential, and cell-specific functions of PI3KĪ² in the ischemic heart. While loss of endothelial PI3KĪ² activity produces cardioprotective effects, cardiomyocyte PI3KĪ² is protective against myocardial ischemic injury

    Workforce scheduling and routing problems: literature survey and computational study

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    In the context of workforce scheduling, there are many scenarios in which personnel must carry out tasks at different locations hence requiring some form of transportation. Examples of these type of scenarios include nurses visiting patients at home, technicians carrying out repairs at customersā€™ locations and security guards performing rounds at different premises, etc. We refer to these scenarios as workforce scheduling and routing problems (WSRP) as they usually involve the scheduling of personnel combined with some form of routing in order to ensure that employees arrive on time at the locations where tasks need to be performed. The first part of this paper presents a survey which attempts to identify the common features of WSRP scenarios and the solution methods applied when tackling these problems. The second part of the paper presents a study on the computational difficulty of solving these type of problems. For this, five data sets are gathered from the literature and some adaptations are made in order to incorporate the key features that our survey identifies as commonly arising in WSRP scenarios. The computational study provides an insight into the structure of the adapted test instances, an insight into the effect that problem features have when solving the instances using mathematical programming, and some benchmark computation times using the Gurobi solver running on a standard personal computer

    Monosodium urate crystals promote innate anti-mycobacterial immunity and improve BCG efficacy as a vaccine against tuberculosis

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    A safer and more effective anti-Tuberculosis vaccine is still an urgent need. We probed the effects of monosodium urate crystals (MSU) on innate immunity to improve the Bacille Calmette-Guerin (BCG) vaccination. Results showed that in vitro MSU cause an enduring macrophage stimulation of the anti-mycobacterial response, measured as intracellular killing, ROS production and phagolysosome maturation. The contribution of MSU to anti-mycobacterial activity was also shown in vivo. Mice vaccinated in the presence of MSU showed a lower number of BCG in lymph nodes draining the vaccine inoculation site, in comparison to mice vaccinated without MSU. Lastly, we showed that MSU improved the efficacy of BCG vaccination in mice infected with Mycobacterium tuberculosis (MTB), measured in terms of lung and spleen MTB burden. These results demonstrate that the use of MSU as adjuvant may represent a novel strategy to enhance the efficacy of BCG vaccination

    The structure of the human tRNALys3 anticodon bound to the HIV genome is stabilized by modified nucleosides and adjacent mismatch base pairs

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    Replication of human immunodeficiency virus (HIV) requires base pairing of the reverse transcriptase primer, human tRNALys3, to the viral RNA. Although the major complementary base pairing occurs between the HIV primer binding sequence (PBS) and the tRNA's 3ā€²-terminus, an important discriminatory, secondary contact occurs between the viral A-rich Loop I, 5ā€²-adjacent to the PBS, and the modified, U-rich anticodon domain of tRNALys3. The importance of individual and combined anticodon modifications to the tRNA/HIV-1 Loop I RNA's interaction was determined. The thermal stabilities of variously modified tRNA anticodon region sequences bound to the Loop I of viral sub(sero)types G and B were analyzed and the structure of one duplex containing two modified nucleosides was determined using NMR spectroscopy and restrained molecular dynamics. The modifications 2-thiouridine, s2U34, and pseudouridine, ĪØ39, appreciably stabilized the interaction of the anticodon region with the viral subtype G and B RNAs. The structure of the duplex results in two coaxially stacked A-form RNA stems separated by two mismatched base pairs, U162ā€¢ĪØ39 and G163ā€¢A38, that maintained a reasonable A-form helix diameter. The tRNA's s2U34 stabilized the interaction between the A-rich HIV Loop I sequence and the U-rich anticodon, whereas the tRNA's ĪØ39 stabilized the adjacent mismatched pairs

    Activation of Aryl Hydrocarbon Receptor (AhR) Leads to Reciprocal Epigenetic Regulation of FoxP3 and IL-17 Expression and Amelioration of Experimental Colitis

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    Aryl hydrocarbon receptor (AhR), a transcription factor of the bHLH/PAS family, is well characterized to regulate the biochemical and toxic effects of environmental chemicals. More recently, AhR activation has been shown to regulate the differentiation of Foxp3(+) Tregs as well as Th17 cells. However, the precise mechanisms are unclear. In the current study, we investigated the effect of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a potent AhR ligand, on epigenetic regulation leading to altered Treg/Th17 differentiation, and consequent suppression of colitis.Dextran sodium sulphate (DSS) administration induced acute colitis in C57BL/6 mice, as shown by significant weight loss, shortening of colon, mucosal ulceration, and increased presence of CXCR3(+) T cells as well as inflammatory cytokines. Interestingly, a single dose of TCDD (25 Āµg/kg body weight) was able to attenuate all of the clinical and inflammatory markers of colitis. Analysis of T cells in the lamina propria (LP) and mesenteric lymph nodes (MLN), during colitis, revealed decreased presence of Tregs and increased induction of Th17 cells, which was reversed following TCDD treatment. Activation of T cells from AhR(+/+) but not AhR (-/-) mice, in the presence of TCDD, promoted increased differentiation of Tregs while inhibiting Th17 cells. Analysis of MLN or LP cells during colitis revealed increased methylation of CpG islands of Foxp3 and demethylation of IL-17 promoters, which was reversed following TCDD treatment.These studies demonstrate for the first time that AhR activation promotes epigenetic regulation thereby influencing reciprocal differentiation of Tregs and Th17 cells, and amelioration of inflammation

    Binding of aminoglycoside antibiotics to helix 69 of 23S rRNA

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    Aminoglycosides antibiotics negate dissociation and recycling of the bacterial ribosomeā€™s subunits by binding to Helix 69 (H69) of 23S rRNA. The differential binding of various aminoglycosides to the chemically synthesized terminal domains of the Escherichia coli and human H69 has been characterized using spectroscopy, calorimetry and NMR. The unmodified E. coli H69 hairpin exhibited a significantly higher affinity for neomycin B and tobramycin than for paromomycin (Kds = 0.3 Ā± 0.1, 0.2 Ā± 0.2 and 5.4 Ā± 1.1 ĀµM, respectively). The binding of streptomycin was too weak to assess. In contrast to the E. coli H69, the human 28S rRNA H69 had a considerable decrease in affinity for the antibiotics, an important validation of the bacterial target. The three conserved pseudouridine modifications (ĪØ1911, ĪØ1915, ĪØ1917) occurring in the loop of the E. coli H69 affected the dissociation constant, but not the stoichiometry for the binding of paromomycin (Kd = 2.6 Ā± 0.1 ĀµM). G1906 and G1921, observed by NMR spectrometry, figured predominantly in the aminoglycoside binding to H69. The higher affinity of the E. coli H69 for neomycin B and tobramycin, as compared to paromomycin and streptomycin, indicates differences in the efficacy of the aminoglycosides

    Reparameterization of RNA Ļ‡ Torsion Parameters for the AMBER Force Field and Comparison to NMR Spectra for Cytidine and Uridine

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    A reparameterization of the torsional parameters for the glycosidic dihedral angle, Ļ‡, for the AMBER99 force field in RNA nucleosides is used to provide a modified force field, AMBER99Ļ‡. Molecular dynamics simulations of cytidine, uridine, adenosine, and guanosine in aqueous solution using the AMBER99 and AMBER99Ļ‡ force fields are compared with NMR results. For each nucleoside and force field, 10 individual molecular dynamics simulations of 30 ns each were run. For cytidine with AMBER99Ļ‡ force field, each molecular dynamics simulation time was extended to 120 ns for convergence purposes. Nuclear magnetic resonance (NMR) spectroscopy, including one-dimensional (1D) 1H, steady-state 1D 1H nuclear Overhauser effect (NOE), and transient 1D 1H NOE, was used to determine the sugar puckering and preferred base orientation with respect to the ribose of cytidine and uridine. The AMBER99 force field overestimates the population of syn conformations of the base orientation and of C2ā€²-endo sugar puckering of the pyrimidines, while the AMBER99Ļ‡ force fieldā€™s predictions are more consistent with NMR results. Moreover, the AMBER99 force field prefers high anti conformations with glycosidic dihedral angles around 310Ā° for the base orientation of purines. The AMBER99Ļ‡ force field prefers anti conformations around 185Ā°, which is more consistent with the quantum mechanical calculations and known 3D structures of folded ribonucleic acids (RNAs). Evidently, the AMBER99Ļ‡ force field predicts the structural characteristics of ribonucleosides better than the AMBER99 force field and should improve structural and thermodynamic predictions of RNA structures
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