64 research outputs found

    The A2A adenosine receptor: its role in suppressing vascular inflammation and its regulation by phosphorylation

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    Endothelial inflammation leading to vascular dysfunction is a major contributor to the development of atherosclerosis. The release of adenosine at sites of inflammation represents an endogenous mechanism for limiting excessive inflammation and tissue damage. The majority of the anti-inflammatory effects of adenosine are mediated by signalling through the A2AAR and activation of the A2AAR has been shown to be protective in numerous models of inflammatory disease. Little is known about the molecular mechanisms behind these effects. However, in vitro studies using cultured endothelial cells indicate that signalling through the A2AAR can suppress activation of the NF kappa B and JAK/STAT proinflammatory signalling pathways. NF kappa B appears to be primed for activation in atherosclerosis-prone regions of the aorta indicating that suppression of NF kappa B signalling may protect against the development of atherosclerosis. In this study, the role of the A2AAR in regulating NF kappa B and JAK/STAT signalling pathway activation in the aorta was studied using A2AAR-deficient mice subjected to an LPS-induced model of septic shock. In response to LPS treatment, these mice displayed markedly elevated plasma levels of the pro-inflammatory cytokines TNF-alpha, IL-6, IL-1 beta and GMCSF compared to wild-type mice. Consistent with this finding, heightened activation of the NF kappa B and JAK/STAT pathways was detected in aortic protein samples from A2AAR-deficient mice as demonstrated by increased levels of the phosphorylated forms of I kappa B alpha and STAT1. However, expression of the NF kappa B and STAT1-regulated genes ICAM-1, VCAM-1 and TAP-1 was unaffected indicating the involvement of compensatory negative feedback mechanisms. These findings confirm a role for the A2AAR in regulation of pro-inflammatory signalling in the aorta. Further analysis of mechanisms which mediate this response may reveal new targets for therapeutic intervention to suppress inflammation in inflammatory disorders such as atherosclerosis. While the wide range of anti-inflammatory and tissue-protective responses elicited by the A2AAR have been well documented, the molecular regulation of the A2AAR has been less well studied. The presence of several serine and threonine residues in the extended C-terminal tail of the A2AAR suggests that it may be regulated by phosphorylation events occurring in this region. Indeed, the canine A2AAR is phosphorylated in response to PKC activation. Interestingly, several proteins have recently been identified as being able to interact with the C-terminal tail of the A2AAR. However, how these interactions are regulated is not known. One of the aims of this study was to characterise phosphorylation of the human A2AAR and to determine whether this could provide a means for regulating the binding of C-terminal interacting proteins. This was examined using human umbilical vein endothelial cells infected with recombinant adenovirus encoding the human A2AAR. It was found that phosphorylation of the human A2AAR could be induced in HUVECs by treatment with PMA or by stimulation of endogenous histamine H1 receptors. This was due to activation of PKC, as phosphorylation was inhibited by the PKC inhibitor GF109203X and by depletion of PKC following chronic treatment with PMA. Treatment of cells with the calcium-chelating agent BAPTA/AM did not inhibit PMA-induced phosphorylation indicating that a calcium-insensitive isoform of PKC was responsible. Meanwhile an siRNA-mediated gene silencing approach confirmed that PKC epsilon was not responsible indicating the involvement of either PKC delta or PKC theta. Previously reported interactions between the A2AAR and TRAX and 14-3-3 tau were confirmed in vitro by GST pull-down assay. Binding of 14-3-3 tau to the A2AAR appeared to be unaffected by treatment of HUVECs with PMA. However, A2AAR complex formation with TRAX was significantly reduced in samples from PMA-stimulated cells. These findings indicate that PKC-mediated phosphorylation may represent a means of regulating which proteins can interact with the C-terminal tail of the A2AAR. This may allow the A2AAR to initiate distinct signalling pathways depending on the cellular context in order to achieve the appropriate response

    The Viscoelastic Properties of the Fungal Cell Wall Allow Traffic of AmBisome as Intact Liposome Vesicles

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    NARG thanks The Wellcome Trust (080088, 086827, 075470, 099215 & 097377) and MRC Centre for Medical Mycology (MR/N006364/1) and acknowledges financial support from Gilead Sciences for a studentship and grant IX-EU-131-0262. Dr. Linda Soo Hoo and Tark Bunch of Gilead provided expert technical assistance in liposomal sample preparations and GF provided gold labelled test articles. JAM is funded in part from a research grant from Gilead Sciences Inc. ML was supported by the MRC (MR/J008230/1). AC was supported in part by 5R01HL059842, 5R01AI033774, 5R37AI033142, and 5R01AI052733. We thank Debbie Wilkinson and Kevin McKenzie at the Imaging Core Facility at the University of Aberdeen for expert assistance with TEM.Peer reviewedPublisher PD

    What makes it so hard to look and to listen? Exploring the use of the Cognitive and Affective Supervisory Approach with children’s social work managers

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    This paper reports on the findings of an ESRC-funded Knowledge Exchange project designed to explore the contribution of an innovative approach to supervision to social work practitioners’ assessment and decision-making practices. The Cognitive and Affective Supervisory Approach (CASA) is informed by cognitive interviewing techniques originally designed to elicit best evidence from witnesses and victims of crime. Adapted here for use in childcare social work supervision contexts, this model is designed to enhance the quantity and quality of information available for decision-making. Facilitating the reporting of both ‘event information’ and ‘emotion information’, it allows a more detailed picture to emerge of events, as recalled by the individual involved, and the meaning they give to them. Practice supervisors from Children’s Services in two local authorities undertook to introduce the CASA into supervision sessions and were supported in this through the provision of regular reflective group discussions. The project findings highlight the challenges for practitioners of ‘detailed looking’ and for supervisors of ‘active listening’. The paper concludes by acknowledging that the CASA’s successful contribution to decision-making is contingent on both the motivation and confidence of supervisors to develop their skills and an organisational commitment to, and resourcing of, reflective supervisory practices and spaces

    High Viral Diversity and Mixed Infections in Cerebral Spinal Fluid From Cases of Varicella Zoster Virus Encephalitis.

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    BACKGROUND: Varicella zoster virus (VZV) may cause encephalitis, both with and without rash. Here we investigate whether viruses recovered from the central nervous system (CNS; encephalitis or meningitis) differ genetically from those recovered from non-CNS samples. METHODS: Enrichment-based deep sequencing of 45 VZV genomes from cerebral spinal fluid (CSF), plasma, bronchoalveolar lavage (BAL), and vesicles was carried out with samples collected from 34 patients with and without VZV infection of the CNS. RESULTS: Viral sequences from multiple sites in the same patient were identical at the consensus level. Virus from vesicle fluid and CSF in cases of meningitis showed low-level diversity. By contrast, plasma, BAL, and encephalitis had higher numbers of variant alleles. Two CSF-encephalitis samples had high genetic diversity, with variant frequency patterns typical of mixed infections with different clades. CONCLUSIONS: Low viral genetic diversity in vesicle fluid is compatible with previous observations that VZV skin lesions arise from single or low numbers of virions. A similar result was observed in VZV from cases of VZV meningitis, a generally self-limiting infection. CSF from cases of encephalitis had higher diversity with evidence for mixed clade infections in 2 cases. We hypothesize that reactivation from multiple neurons may contribute to the pathogenesis of VZV encephalitis.Action Medical research GN2424 This work was supported by a UK MRC New Investigator Award to D. P. D; UCL/UCLH BRC (J. B.); Action Medical Research (grant number GN2424 to C. J. H); Swedish Research Council (P. N. and T. B.). The work was also support by an NIHR Fellowship (grant number DRF-2013-06-168 to F. M.), the Meningitis Research Foundation (grant number 0904.0), an NIHR Programme Grant in Applied Research (grant number RP-PG-0108-10048 to T. S.), and the NIHR Health Protection Research Unit in Emerging and Zoonotic Infections, University of Liverpool

    Fat Oxidation, Fitness and Skeletal Muscle Expression of Oxidative/Lipid Metabolism Genes in South Asians: Implications for Insulin Resistance?

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    <p><b>Background:</b> South Asians are more insulin resistant than Europeans, which cannot be fully explained by differences in adiposity. We investigated whether differences in oxidative capacity and capacity for fatty acid utilisation in South Asians might contribute, using a range of whole-body and skeletal muscle measures.</p> <p><b>Methodology/Principal Findings:</b> Twenty men of South Asian ethnic origin and 20 age and BMI-matched men of white European descent underwent exercise and metabolic testing and provided a muscle biopsy to determine expression of oxidative and lipid metabolism genes and of insulin signalling proteins. In analyses adjusted for age, BMI, fat mass and physical activity, South Asians, compared to Europeans, exhibited; reduced insulin sensitivity by 26% (p = 0.010); lower VO2max (40.6±6.6 vs 52.4±5.7 ml.kg−1.min−1, p = 0.001); and reduced fat oxidation during submaximal exercise at the same relative (3.77±2.02 vs 6.55±2.60 mg.kg−1.min−1 at 55% VO2max, p = 0.013), and absolute (3.46±2.20 vs 6.00±1.93 mg.kg−1.min−1 at 25 ml O2.kg−1.min−1, p = 0.021), exercise intensities. South Asians exhibited significantly higher skeletal muscle gene expression of CPT1A and FASN and significantly lower skeletal muscle protein expression of PI3K and PKB Ser473 phosphorylation. Fat oxidation during submaximal exercise and VO2max both correlated significantly with insulin sensitivity index and PKB Ser473 phosphorylation, with VO2max or fat oxidation during exercise explaining 10–13% of the variance in insulin sensitivity index, independent of age, body composition and physical activity.</p> <p><b>Conclusions/Significance:</b> These data indicate that reduced oxidative capacity and capacity for fatty acid utilisation at the whole body level are key features of the insulin resistant phenotype observed in South Asians, but that this is not the consequence of reduced skeletal muscle expression of oxidative and lipid metabolism genes.</p&gt

    No evidence that protein truncating variants in BRIP1 are associated with breast cancer risk: implications for gene panel testing.

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    BACKGROUND: BRCA1 interacting protein C-terminal helicase 1 (BRIP1) is one of the Fanconi Anaemia Complementation (FANC) group family of DNA repair proteins. Biallelic mutations in BRIP1 are responsible for FANC group J, and previous studies have also suggested that rare protein truncating variants in BRIP1 are associated with an increased risk of breast cancer. These studies have led to inclusion of BRIP1 on targeted sequencing panels for breast cancer risk prediction. METHODS: We evaluated a truncating variant, p.Arg798Ter (rs137852986), and 10 missense variants of BRIP1, in 48 144 cases and 43 607 controls of European origin, drawn from 41 studies participating in the Breast Cancer Association Consortium (BCAC). Additionally, we sequenced the coding regions of BRIP1 in 13 213 cases and 5242 controls from the UK, 1313 cases and 1123 controls from three population-based studies as part of the Breast Cancer Family Registry, and 1853 familial cases and 2001 controls from Australia. RESULTS: The rare truncating allele of rs137852986 was observed in 23 cases and 18 controls in Europeans in BCAC (OR 1.09, 95% CI 0.58 to 2.03, p=0.79). Truncating variants were found in the sequencing studies in 34 cases (0.21%) and 19 controls (0.23%) (combined OR 0.90, 95% CI 0.48 to 1.70, p=0.75). CONCLUSIONS: These results suggest that truncating variants in BRIP1, and in particular p.Arg798Ter, are not associated with a substantial increase in breast cancer risk. Such observations have important implications for the reporting of results from breast cancer screening panels.The COGS project is funded through a European Commission's Seventh Framework Programme grant (agreement number 223175 - HEALTH-F2-2009-223175). BCAC is funded by Cancer Research UK [C1287/A10118, C1287/A12014] and by the European Community´s Seventh Framework Programme under grant agreement number 223175 (grant number HEALTH-F2-2009-223175) (COGS). Funding for the iCOGS infrastructure came from: the European Community's Seventh Framework Programme under grant agreement n° 223175 (HEALTH-F2-2009-223175) (COGS), Cancer Research UK (C1287/A10118, C1287/A 10710, C12292/A11174, C1281/A12014, C5047/A8384, C5047/A15007, C5047/A10692, C8197/A16565), the National Institutes of Health (CA128978) and Post-Cancer GWAS initiative (1U19 CA148537, 1U19 16 CA148065 and 1U19 CA148112 - the GAME-ON initiative), the Department of Defense (W81XWH-10-1- 0341), the Canadian Institutes of Health Research (CIHR) for the CIHR Team in Familial Risks of Breast Cancer, Komen Foundation for the Cure, the Breast Cancer Research Foundation, and the Ovarian Cancer Research Fund. This study made use of data generated by the Wellcome Trust Case Control consortium. Funding for the project was provided by the Wellcome Trust under award 076113. The results published here are in part based upon data generated by The Cancer Genome Atlas Project established by the National Cancer Institute and National Human Genome Research Institute.This is the author accepted manuscript. The final version is available from BMJ Group at http://dx.doi.org/10.1136/jmedgenet-2015-103529

    The Influence of Number and Timing of Pregnancies on Breast Cancer Risk for Women With BRCA1 or BRCA2 Mutations

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    International audienceBACKGROUND:Full-term pregnancy (FTP) is associated with a reduced breast cancer (BC) risk over time, but women are at increased BC risk in the immediate years following an FTP. No large prospective studies, however, have examined whether the number and timing of pregnancies are associated with BC risk for BRCA1 and BRCA2 mutation carriers.METHODS:Using weighted and time-varying Cox proportional hazards models, we investigated whether reproductive events are associated with BC risk for mutation carriers using a retrospective cohort (5707 BRCA1 and 3525 BRCA2 mutation carriers) and a prospective cohort (2276 BRCA1 and 1610 BRCA2 mutation carriers), separately for each cohort and the combined prospective and retrospective cohort.RESULTS:For BRCA1 mutation carriers, there was no overall association with parity compared with nulliparity (combined hazard ratio [HRc] = 0.99, 95% confidence interval [CI] = 0.83 to 1.18). Relative to being uniparous, an increased number of FTPs was associated with decreased BC risk (HRc = 0.79, 95% CI = 0.69 to 0.91; HRc = 0.70, 95% CI = 0.59 to 0.82; HRc = 0.50, 95% CI = 0.40 to 0.63, for 2, 3, and ≥4 FTPs, respectively, P trend < .0001) and increasing duration of breastfeeding was associated with decreased BC risk (combined cohort P trend = .0003). Relative to being nulliparous, uniparous BRCA1 mutation carriers were at increased BC risk in the prospective analysis (prospective hazard ration [HRp] = 1.69, 95% CI = 1.09 to 2.62). For BRCA2 mutation carriers, being parous was associated with a 30% increase in BC risk (HRc = 1.33, 95% CI = 1.05 to 1.69), and there was no apparent decrease in risk associated with multiparity except for having at least 4 FTPs vs. 1 FTP (HRc = 0.72, 95% CI = 0.54 to 0.98).CONCLUSIONS:These findings suggest differential associations with parity between BRCA1 and BRCA2 mutation carriers with higher risk for uniparous BRCA1 carriers and parous BRCA2 carriers

    Breast cancer risk variants at 6q25 display different phenotype associations and regulate ESR1, RMND1 and CCDC170.

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    We analyzed 3,872 common genetic variants across the ESR1 locus (encoding estrogen receptor α) in 118,816 subjects from three international consortia. We found evidence for at least five independent causal variants, each associated with different phenotype sets, including estrogen receptor (ER(+) or ER(-)) and human ERBB2 (HER2(+) or HER2(-)) tumor subtypes, mammographic density and tumor grade. The best candidate causal variants for ER(-) tumors lie in four separate enhancer elements, and their risk alleles reduce expression of ESR1, RMND1 and CCDC170, whereas the risk alleles of the strongest candidates for the remaining independent causal variant disrupt a silencer element and putatively increase ESR1 and RMND1 expression.This is the author accepted manuscript. The final version is available from Nature Publishing Group via http://dx.doi.org/10.1038/ng.352

    Identification of a BRCA2-Specific modifier locus at 6p24 related to breast cancer risk

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    Common genetic variants contribute to the observed variation in breast cancer risk for BRCA2 mutation carriers; those known to date have all been found through population-based genome-wide association studies (GWAS). To comprehensively identify breast cancer risk modifying loci for BRCA2 mutation carriers, we conducted a deep replication of an ongoing GWAS discovery study. Using the ranked P-values of the breast cancer associations with the imputed genotype of 1.4 M SNPs, 19,029 SNPs were selected and designed for inclusion on a custom Illumina array that included a total of 211,155 SNPs as part of a multi-consortial project. DNA samples from 3,881 breast cancer affected and 4,330 unaffected BRCA2 mutation carriers from 47 studies belonging to the Consortium of Investigators of Modifiers of BRCA1/2 were genotyped and available for analysis. We replicated previously reported breast cancer susceptibility alleles in these BRCA2 mutation carriers and for several regions (including FGFR2, MAP3K1, CDKN2A/B, and PTHLH) identified SNPs that have stronger evidence of association than those previously published. We also identified a novel susceptibility allele at 6p24 that was inversely associated with risk in BRCA2 mutation carriers (rs9348512; per allele HR = 0.85, 95% CI 0.80-0.90, P = 3.9×10−8). This SNP was not associated with breast cancer risk either in the general population or in BRCA1 mutation carriers. The locus lies within a region containing TFAP2A, which encodes a transcriptional activation protein that interacts with several tumor suppressor genes. This report identifies the first breast cancer risk locus specific to a BRCA2 mutation background. This comprehensive update of novel and previously reported breast cancer susceptibility loci contributes to the establishment of a panel of SNPs that modify breast cancer risk in BRCA2 mutation carriers. This panel may have clinical utility for women with BRCA2 mutations weighing options for medical prevention of breast cancer

    Identification of 12 new susceptibility loci for different histotypes of epithelial ovarian cancer.

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    To identify common alleles associated with different histotypes of epithelial ovarian cancer (EOC), we pooled data from multiple genome-wide genotyping projects totaling 25,509 EOC cases and 40,941 controls. We identified nine new susceptibility loci for different EOC histotypes: six for serous EOC histotypes (3q28, 4q32.3, 8q21.11, 10q24.33, 18q11.2 and 22q12.1), two for mucinous EOC (3q22.3 and 9q31.1) and one for endometrioid EOC (5q12.3). We then performed meta-analysis on the results for high-grade serous ovarian cancer with the results from analysis of 31,448 BRCA1 and BRCA2 mutation carriers, including 3,887 mutation carriers with EOC. This identified three additional susceptibility loci at 2q13, 8q24.1 and 12q24.31. Integrated analyses of genes and regulatory biofeatures at each locus predicted candidate susceptibility genes, including OBFC1, a new candidate susceptibility gene for low-grade and borderline serous EOC
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