38 research outputs found

    Circulating levels of insulin-like growth factor-I (IGF-I) correlate with disease status in leprosy

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    <p>Abstract</p> <p>Background</p> <p>Caused by <it>Mycobacterium leprae </it>(ML), leprosy presents a strong immune-inflammatory component, whose status dictates both the clinical form of the disease and the occurrence of reactional episodes. Evidence has shown that, during the immune-inflammatory response to infection, the growth hormone/insulin-like growth factor-I (GH/IGF-I) plays a prominent regulatory role. However, in leprosy, little, if anything, is known about the interaction between the immune and neuroendocrine systems.</p> <p>Methods</p> <p>In the present retrospective study, we measured the serum levels of IGF-I and IGBP-3, its major binding protein. These measurements were taken at diagnosis in nonreactional borderline tuberculoid (NR BT), borderline lepromatous (NR BL), and lepromatous (NR LL) leprosy patients in addition to healthy controls (HC). LL and BL patients who developed reaction during the course of the disease were also included in the study. The serum levels of IGF-I, IGFBP-3 and tumor necrosis factor-alpha (TNF-α) were evaluated at diagnosis and during development of reversal (RR) or erythema nodosum leprosum (ENL) reaction by the solid phase, enzyme-labeled, chemiluminescent-immunometric method.</p> <p>Results</p> <p>The circulating IGF-I/IGFBP-3 levels showed significant differences according to disease status and occurrence of reactional episodes. At the time of leprosy diagnosis, significantly lower levels of circulating IGF-I/IGFBP-3 were found in NR BL and NR LL patients in contrast to NR BT patients and HCs. However, after treatment, serum IGF-I levels in BL/LL patients returned to normal. Notably, the levels of circulating IGF-I at diagnosis were low in 75% of patients who did not undergo ENL during treatment (NR LL patients) in opposition to the normal levels observed in those who suffered ENL during treatment (R LL patients). Nonetheless, during ENL episodes, the levels observed in RLL sera tended to decrease, attaining similar levels to those found in NR LL patients. Interestingly, IGF-I behaved contrary to what was observed during RR episodes in R BL patients.</p> <p>Conclusions</p> <p>Our data revealed important alterations in the IGF system in relation to the status of the host immune-inflammatory response to ML while at the same time pointing to the circulating IGF-I/IGFBP-3 levels as possible predictive biomarkers for ENL in LL patients at diagnosis.</p

    Endothelial cells use dynamic actin to facilitate lymphocyte transendothelial migration and maintain the monolayer barrier

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    The vascular endothelium is a highly dynamic structure, and the integrity of its barrier function is tightly regulated. Normally impenetrable to cells, the endothelium actively assists lymphocytes to exit the bloodstream during inflammation. The actin cytoskeleton of the endothelial cell (EC) is known to facilitate transmigration, but the cellular and molecular mechanisms are not well understood. Here we report that actin assembly in the EC, induced by Arp2/3 complex under control of WAVE2, is important for several steps in the process of transmigration. To begin transmigration, ECs deploy actin-based membrane protrusions that create a cup-shaped docking structure for the lymphocyte. We found that docking structure formation involves the localization and activation of Arp2/3 complex by WAVE2. The next step in transmigration is creation of a migratory pore, and we found that endothelial WAVE2 is needed for lymphocytes to follow a transcellular route through an EC. Later, ECs use actin-based protrusions to close the gap behind the lymphocyte, which we discovered is also driven by WAVE2. Finally, we found that ECs in resting endothelial monolayers use lamellipodial protrusions dependent on WAVE2 to form and maintain contacts and junctions between cells

    Frequent Long-Range Epigenetic Silencing of Protocadherin Gene Clusters on Chromosome 5q31 in Wilms' Tumor

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    Wilms' tumour (WT) is a pediatric tumor of the kidney that arises via failure of the fetal developmental program. The absence of identifiable mutations in the majority of WTs suggests the frequent involvement of epigenetic aberrations in WT. We therefore conducted a genome-wide analysis of promoter hypermethylation in WTs and identified hypermethylation at chromosome 5q31 spanning 800 kilobases (kb) and more than 50 genes. The methylated genes all belong to α-, β-, and γ-protocadherin (PCDH) gene clusters (Human Genome Organization nomenclature PCDHA@, PCDHB@, and PCDHG@, respectively). This demonstrates that long-range epigenetic silencing (LRES) occurs in developmental tumors as well as in adult tumors. Bisulfite polymerase chain reaction analysis showed that PCDH hypermethylation is a frequent event found in all Wilms' tumor subtypes. Hypermethylation is concordant with reduced PCDH expression in tumors. WT precursor lesions showed no PCDH hypermethylation, suggesting that de novo PCDH hypermethylation occurs during malignant progression. Discrete boundaries of the PCDH domain are delimited by abrupt changes in histone modifications; unmethylated genes flanking the LRES are associated with permissive marks which are absent from methylated genes within the domain. Silenced genes are marked with non-permissive histone 3 lysine 9 dimethylation. Expression analysis of embryonic murine kidney and differentiating rat metanephric mesenchymal cells demonstrates that Pcdh expression is developmentally regulated and that Pcdhg@ genes are expressed in blastemal cells. Importantly, we show that PCDHs negatively regulate canonical Wnt signalling, as short-interfering RNA–induced reduction of PCDHG@ encoded proteins leads to elevated β-catenin protein, increased β-catenin/T-cell factor (TCF) reporter activity, and induction of Wnt target genes. Conversely, over-expression of PCDHs suppresses β-catenin/TCF-reporter activity and also inhibits colony formation and growth of cancer cells in soft agar. Thus PCDHs are candidate tumor suppressors that modulate regulatory pathways critical in development and disease, such as canonical Wnt signaling

    Role of glutamine synthetase in angiogenesis beyond glutamine synthesis

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    Glutamine synthetase, encoded by the gene GLUL, is an enzyme that converts glutamate and ammonia to glutamine. It is expressed by endothelial cells, but surprisingly shows negligible glutamine-synthesizing activity in these cells at physiological glutamine levels. Here we show in mice that genetic deletion of Glul in endothelial cells impairs vessel sprouting during vascular development, whereas pharmacological blockade of glutamine synthetase suppresses angiogenesis in ocular and inflammatory skin disease while only minimally affecting healthy adult quiescent endothelial cells. This relies on the inhibition of endothelial cell migration but not proliferation. Mechanistically we show that in human umbilical vein endothelial cells GLUL knockdown reduces membrane localization and activation of the GTPase RHOJ while activating other Rho GTPases and Rho kinase, thereby inducing actin stress fibres and impeding endothelial cell motility. Inhibition of Rho kinase rescues the defect in endothelial cell migration that is induced by GLUL knockdown. Notably, glutamine synthetase palmitoylates itself and interacts with RHOJ to sustain RHOJ palmitoylation, membrane localization and activation. These findings reveal that, in addition to the known formation of glutamine, the enzyme glutamine synthetase shows unknown activity in endothelial cell migration during pathological angiogenesis through RHOJ palmitoylation

    The association between objectively measured physical activity and morning symptoms in COPD

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    Amanda R van Buul,1 Marise J Kasteleyn,1,2 Niels H Chavannes,2 Christian Taube1,3 1Department of Pulmonology, 2Department of Public Health and Primary Care, Leiden University Medical Center, Leiden, the Netherlands; 3Department of Pulmonary Medicine, West German Lung Center, Essen University Hospital, Ruhrlandklinik, University Duisburg-Essen, Essen, Germany Purpose: The morning is the most bothersome period for COPD patients. Morning symptom severities in different Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages are not well studied. Furthermore, factors that are associated with morning symptoms, especially the associations with objectively measured physical activity, are also not well described.Materials and methods: The aim of this cross-sectional observational study was to assess morning symptom severity in GOLD A, B, C and D patients, according to the definitions of the GOLD 2015 statement. Morning symptoms were assessed with the PRO-Morning COPD Symptoms Questionnaire. Differences in morning symptom severity between different COPD stages were assessed with a one-way analysis of variance followed by post hoc analyses. The association between dyspnea severity (assessed with the modified Medical Research Council scale), health status, airflow limitation, lung hyperinflation, anxiety and depression, inflammatory parameters, exacerbations, objectively measured physical activity parameters retrieved from accelerometry and morning symptom severity was evaluated using linear regression analysis.Results: Eighty patients were included (aged 65.6&plusmn;8.7 years, forced expiratory volume in 1 second [FEV1] % predicted 55.1&plusmn;16.9). Mean (&plusmn;SD) morning symptom score was 19.7 (&plusmn;11.7). Morning symptom severity was significantly different between COPD stages: mean (&plusmn;SD) score in GOLD A was 9.7 (&plusmn;7.2), in GOLD B 19.8 (&plusmn;10.7), in GOLD C 8.6 (&plusmn;9.3) and in GOLD D 23.8 (&plusmn;11.2) (p&lt;0.001). Lower health status, more symptoms, increased anxiety and depression, less physical activity (all p&lt;0.001) and lower FEV1 (p=0.03) were associated with an increased morning symptom severity.Conclusion: Patients with overall more symptomatic COPD have significant higher morning symptom scores. Morning symptom severity was associated with important clinical outcomes: lower health status, more symptoms, increased anxiety and depression, fewer steps a day, less time in moderate and vigorous physical activity with bouts of at least 10 minutes and lower FEV1. The data suggest that morning symptoms should be carefully assessed in addition to assessment by general COPD-specific questionnaires, especially in those with more symptomatic COPD. More research is needed on potential therapies to improve morning symptoms; this study shows potential targets for intervention. Keywords: accelerometry, chronic obstructive pulmonary disease, physical activity, PRO-Morning COPD Symptoms Questionnaire, morning symptom

    Adverse drug reactions in a primary care population prescribed non-steroidal anti-inflammatory drugs

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    Objective. To determine how often patients with musculoskeletal (MSK) complaints prescribed a non-steroidal anti-inflammatory drug (NSAID) subsequently consult their general practitioner (GP) with a non-serious adverse drug reaction (ADR). Design. Cohort study. Setting. A healthcare database containing the electronic GP medical records of over 1.5 million patients throughout the Netherlands. Patients. A total of 16 626 adult patients with MSK complaints prescribed an NSAID. Main outcome measures. The patients' medical records were manually assessed for the duration of NSAID use for a maximum of two months, and consultations for complaints predefined as potential ADRs were identified. Subsequently, the likelihood of an association with the NSAID use was assessed and these potential ADRs were categorized as likely, possible, or unlikely ADRs. Results. In total, 961 patients (6%) consulted their GP with 1227 non-serious potential ADRs. In 174 patients (1%) at least one of these was categorized as a likely ADR, and in a further 408 patients (2.5%) at least one was categorized as a possible ADR. Dyspepsia was the most frequent likely ADR, followed by diarrhoea and dyspnoea (respectively 34%, 8%, and 8% of all likely ADRs). Conclusion. Of the patients with MSK complaints prescribed an NSAID, almost one in 30 patients re-consulted their GP with a complaint likely or possibly associated with the use of this drug. The burden of such consultations for non-serious ADRs should be taken into account by GPs when deciding whether treatment with an NSAID is appropriate

    Recent insights into endothelial control of leukocyte extravasation

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    In the process of leukocyte migration from the circulation across the vascular wall, the crosstalk with endothelial cells that line the blood vessels is essential. It is now firmly established that in endothelial cells important signaling events are initiated upon leukocyte adhesion that impinge on the regulation of cell-cell contact and control the efficiency of transendothelial migration. In addition, several external factors such as shear force and vascular stiffness were recently identified as important regulators of endothelial signaling and, consequently, leukocyte transmigration. Here, I review recent insights into endothelial signaling events that are linked to leukocyte migration across the vessel wall. In this field, protein phosphorylation and Rho-mediated cytoskeletal dynamics are still widely studied using increasingly sophisticated mouse models. In addition, activation of tyrosine phosphatases, changes in endothelial cell stiffness as well as different vascular beds have all been established as important factors in endothelial signaling and leukocyte transmigration. Finally, I address less-well-studied but interesting components in the endothelium that also control transendothelial migration, such as the ephrins and their Eph receptors, that provide novel insights in the complexity associated with this proces
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