143 research outputs found

    Phosphoinositide 3 kinase signalling may affect multiple steps during herpes simplex virus type-1 entry

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    Early interactions of herpes simplex virus type-1 (HSV-1) with cells lead to cytoskeletal changes facilitating filopodia formation and membrane fusion. Here, we demonstrate that phosphoinositide 3 kinase (PI3K) signalling may affect multiple steps during HSV-1 entry. An inhibitor of PI3K (LY294002) blocked HSV-1 entry and the blockage was cell-type- and gD receptor-independent. Entry inhibition was also observed with primary cultures of the human corneal fibroblasts and unrelated β- and γ-herpesviruses. Immunofluorescence analysis demonstrated that LY294002 negatively affected HSV-1-induced filopodia formation. Similar effects of the inhibitor were seen on HSV-1 glycoprotein-induced cell-to-cell fusion. Cells expressing HSV-1 glycoproteins (gB, gD, gH and gL) showed significantly less fusion with target cells in the presence of the inhibitor. Expression of a dominant-negative PI3K mutant negatively affected both entry and fusion. We also show that inhibition of PI3K signalling also affected RhoA activation required for HSV-1 entry into certain cell types

    Distribution and biological role of the oligopeptide-binding protein (OppA) in Xanthomonas species

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    In this study we investigated the prevalence of the oppA gene, encoding the oligopeptide binding protein (OppA) of the major bacterial oligopeptide uptake system (Opp), in different species of the genus Xanthomonas. The oppA gene was detected in two Xanthomonas axonopodis strains among eight tested Xanthomonas species. The generation of an isogenic oppA-knockout derivative of the Xac 306 strain, showed that the OppA protein neither plays a relevant role in oligopeptide uptake nor contributes to the infectivity and multiplication of the bacterial strain in leaves of sweet orange (Citrus sinensis) and Rangpur lime (Citrus limonia). Taken together these results suggest that the oppA gene has a recent evolutionary history in the genus and does not contribute in the physiology or pathogenesis of X. axonopodis

    Participation of the PI-3K/Akt-NF-κB signaling pathways in hypoxia-induced mitogenic factor-stimulated Flk-1 expression in endothelial cells

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    BACKGROUND: Hypoxia-induced mitogenic factor (HIMF), a lung-specific growth factor, promotes vascular tubule formation in a matrigel plug model. We initially found that HIMF enhances vascular endothelial growth factor (VEGF) expression in lung epithelial cells. In present work, we tested whether HIMF modulates expression of fetal liver kinase-1 (Flk-1) in endothelial cells, and dissected the possible signaling pathways that link HIMF to Flk-1 upregulation. METHODS: Recombinant HIMF protein was intratracheally instilled into adult mouse lungs, Flk-1 expression was examined by immunohistochemistry and Western blot. The promoter-luciferase reporter assay and real-time RT-PCR were performed to examine the effects of HIMF on Flk-1 expression in mouse endothelial cell line SVEC 4–10. The activation of NF-kappa B (NF-κB) and phosphorylation of Akt, IKK, and IκBα were examined by luciferase assay and Western blot, respectively. RESULTS: Intratracheal instillation of HIMF protein resulted in a significant increase of Flk-1 production in lung tissues. Stimulation of SVEC 4–10 cells by HIMF resulted in increased phosphorylation of IKK and IκBα, leading to activation of NF-κB. Blocking NF-κB signaling pathway by dominant-negative mutants of IKK and IκBα suppressed HIMF-induced Flk-1 upregulation. Mutation or deletion of NF-κB binding site within Flk-1 promoter also abolished HIMF-induced Flk-1 expression in SVEC 4–10 cells. Furthermore, HIMF strongly induced phosphorylation of Akt. A dominant-negative mutant of PI-3K, Δp85, as well as PI-3K inhibitor LY294002, blocked HIMF-induced NF-κB activation and attenuated Flk-1 production. CONCLUSION: These results suggest that HIMF upregulates Flk-1 expression in endothelial cells in a PI-3K/Akt-NF-κB signaling pathway-dependent manner, and may play critical roles in pulmonary angiogenesis

    ADAM15 mediates upregulation of Claudin-1 expression in breast cancer cells

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    A Disintegrin and Metalloproteinase-15 (ADAM15) is a transmembrane protein involved in protein ectodomain shedding, cell adhesion and signalling. We previously cloned and characterised alternatively spliced variants of ADAM15 that differ in their intracellular domains and demonstrated correlation of the expression of specific variants with breast cancer prognosis. In this study we have created isogenic cell panels (MDA-MB-231 and MCF-7) expressing five ADAM15 variants including wildtype and catalytically inactive forms. The expression of ADAM15 isoforms in MDA-MB-231 cells led to cell clustering to varying degree, without changes in EMT markers vimentin, slug and E-cadherin. Analysis of tight junction molecules revealed ADAM15 isoform specific, catalytic function dependent upregulation of Claudin-1. The expression of ADAM15A, and to a lesser degree of C and E isoforms led to an increase in Claudin-1 expression in MDA-MB-231 cells, while ADAM15B had no effect. In MCF-7 cells, ADAM15E was the principal variant inducing Claudin-1 expression. Sh-RNA mediated down-regulation of ADAM15 in ADAM15 over-expressing cells reduced Claudin-1 levels. Additionally, downregulation of endogenous ADAM15 expression in T47D cells by shRNA reduced endogenous Claudin-1 expression confirming a role for ADAM15 in regulating Claudin-1 expression. The PI3K/Akt/mTOR pathway was involved in regulating Claudin-1 expression downstream of ADAM15. Immunofluorescence analysis of MDA-MB-231 ADAM15A expressing cells showed Claudin-1 at cell-cell junctions, in the cytoplasm and nuclei. ADAM15 co-localised with Claudin-1 and ZO1 at cell-cell junctions. Immunoprecipitation analysis demonstrated complex formation between ADAM15 and ZO1/ZO2. These findings highlight the importance of ADAM15 Intra Cellular Domain-mediated interactions in regulating substrate selection and breast cancer cell phenotype

    Psychosocial Needs of Children in Foster Care and the Impact of Sexual Abuse

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    Children in family foster care, especially those who have experienced sexual abuse, require a safe and nurturing environment in which their psychosocial needs are met. However, there is limited knowledge on how youth prioritize various needs and what impact previous experiences have on these needs. In this study, we asked youth (formerly) in family foster care to indicate their psychosocial needs, and analyzed if youth with a history of sexual abuse have different needs. A Q methodological study was conducted with 44 youth (age 16–28). Fifteen of them reported sexual abuse during their childhood. Using by-person factor analyses, respondents who share similar subjective views were grouped together. Qualitative interpretations of the factors show differences and similarities between and within the two groups, related to help from others, being independent, processing the past, and working toward the future. Although the needs of youth with and without experiences of sexual abuse seem mostly similar, one group of sexually abused youth specifically indicated not wanting an emotional connection to foster parents, but instead a strictly instrumental, professional relationship. This study captured the diverse perspectives of youth themselves, revealing that children in foster care differ with regard to what they consider as (most) important safety, belonging, self-esteem and self-actualization needs

    Chronic pain, depression and cardiovascular disease linked through a shared genetic predisposition:Analysis of a family-based cohort and twin study

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    BACKGROUND: Depression and chronic pain are the two most important causes of disability (Global Burden of Disease Study 2013). They occur together more frequently than expected and both conditions have been shown to be co-morbid with cardiovascular disease. Although shared socio-demographic risk factors (e.g. gender, deprivation) might explain the co-morbidity of these three conditions, we hypothesised that these three long-term, highly prevalent conditions co-occur and may be due to shared familial risk, and/or genetic factors. METHODS AND FINDINGS: We employed three different study designs in two independent cohorts, namely Generation Scotland and TwinsUK, having standardised, validated questionnaire data on the three traits of interest. First, we estimated the prevalence and co-occurrence of chronic pain, depression and angina among 24,024 participants of a population-based cohort of extended families (Generation Scotland: Scottish Family Health Study), adjusting for age, gender, education, smoking status, and deprivation. Secondly, we compared the odds of co-morbidity in sibling-pairs with the odds in unrelated individuals for the three conditions in the same cohort. Lastly, examination of similar traits in a sample of female twins (TwinsUK, n = 2,902), adjusting for age and BMI, allowed independent replication of the findings and exploration of the influence of additive genetic (A) factors and shared (C) and non-shared (E) environmental factors predisposing to co-occurring chronic widespread pain (CWP) and cardiovascular disease (hypertension, angina, stroke, heart attack, elevated cholesterol, angioplasty or bypass surgery). In the Generation Scotland cohort, individuals with depression were more than twice as likely to have chronic pain as those without depression (adjusted OR 2·64 [95% CI 2·34-2·97]); those with angina were four times more likely to have chronic pain (OR 4·19 [3·64-4·82]); those with depression were twice as likely to have angina (OR 2·20 [1·90-2·54]). Similar odds were obtained when the outcomes and predictors were reversed and similar effects seen among sibling pairs; depression in one sibling predicted chronic pain in the other (OR 1·34 [1·05-1·71]), angina predicted chronic pain in the other (OR 2·19 [1·63-2·95]), and depression, angina (OR 1·98 [1·49-2·65]). Individuals with chronic pain and angina showed almost four-fold greater odds of depression compared with those manifesting neither trait (OR 3·78 [2·99-4·78]); angina showed seven-fold increased odds in the presence of chronic pain and depression (OR 7·76 [6·05-9·95]) and chronic pain nine-fold in the presence of depression and angina (OR 9·43 [6·85-12·98]). In TwinsUK, the relationship between CWP and depression has been published (R = 0.34, p<0.01). Considering the CWP-cardiovascular relationship, the most suitable model to describe the observed data was a combination of A, C and E, with a small but significant genetic predisposition, shared between the two traits (2·2% [95% CI 0·06-0·23]). CONCLUSION: We found an increased co-occurrence of chronic pain, depression and cardiovascular disease in two independent cohorts (general population-based cohort, twins cohort) suggesting a shared genetic contribution. Adjustment for known environmental influences, particularly those relating to socio-economic status (Generation Scotland: age, gender, deprivation, smoking, education; Twins UK: age,BMI) did not explain the relationship observed between chronic pain, depression and cardiovascular disease. Our findings from two independent cohorts challenge the concept of traditional disease boundaries and warrant further investigation of shared biological mechanisms

    Triclocarban Mediates Induction of Xenobiotic Metabolism through Activation of the Constitutive Androstane Receptor and the Estrogen Receptor Alpha

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    Triclocarban (3,4,4′-trichlorocarbanilide, TCC) is used as a broad-based antimicrobial agent that is commonly added to personal hygiene products. Because of its extensive use in the health care industry and resistance to degradation in sewage treatment processes, TCC has become a significant waste product that is found in numerous environmental compartments where humans and wildlife can be exposed. While TCC has been linked to a range of health and environmental effects, few studies have been conducted linking exposure to TCC and induction of xenobiotic metabolism through regulation by environmental sensors such as the nuclear xenobiotic receptors (XenoRs). To identify the ability of TCC to activate xenobiotic sensors, we monitored XenoR activities in response to TCC treatment using luciferase-based reporter assays. Among the XenoRs in the reporter screening assay, TCC promotes both constitutive androstane receptor (CAR) and estrogen receptor alpha (ERα) activities. TCC treatment to hUGT1 mice resulted in induction of the UGT1A genes in liver. This induction was dependent upon the constitutive active/androstane receptor (CAR) because no induction occurred in hUGT1Car−/− mice. Induction of the UGT1A genes by TCC corresponded with induction of Cyp2b10, another CAR target gene. TCC was demonstrated to be a phenobarbital-like activator of CAR in receptor-based assays. While it has been suggested that TCC be classified as an endocrine disruptor, it activates ERα leading to induction of Cyp1b1 in female ovaries as well as in promoter activity. Activation of ERα by TCC in receptor-based assays also promotes induction of human CYP2B6. These observations demonstrate that TCC activates nuclear xenobiotic receptors CAR and ERα both in vivo and in vitro and might have the potential to alter normal physiological homeostasis. Activation of these xenobiotic-sensing receptors amplifies gene expression profiles that might represent a mechanistic base for potential human health effects from exposure to TCC

    Understanding the somatic consequences of depression: biological mechanisms and the role of depression symptom profile

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    ADAM15 mediates upregulation of Claudin-1 expression in breast cancer cells

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    A Disintegrin and Metalloproteinase-15 (ADAM15) is a transmembrane protein involved in protein ectodomain shedding, cell adhesion and signalling. We previously cloned and characterised alternatively spliced variants of ADAM15 that differ in their intracellular domains and demonstrated correlation of the expression of specific variants with breast cancer prognosis. In this study we have created isogenic cell panels (MDA-MB-231 and MCF-7) expressing five ADAM15 variants including wild-type and catalytically inactive forms. The expression of ADAM15 isoforms in MDA-MB-231 cells led to cell clustering to varying degree, without changes in EMT markers vimentin, slug and E-cadherin. Analysis of tight junction molecules revealed ADAM15 isoform specific, catalytic function dependent upregulation of Claudin-1. The expression of ADAM15A, and to a lesser degree of C and E isoforms led to an increase in Claudin-1 expression in MDA-MB-231 cells, while ADAM15B had no effect. In MCF-7 cells, ADAM15E was the principal variant inducing Claudin-1 expression. Sh-RNA mediated down-regulation of ADAM15 in ADAM15 over-expressing cells reduced Claudin-1 levels. Additionally, downregulation of endogenous ADAM15 expression in T47D cells by shRNA reduced endogenous Claudin-1 expression confirming a role for ADAM15 in regulating Claudin-1 expression. The PI3K/Akt/mTOR pathway was involved in regulating Claudin-1 expression downstream of ADAM15. Immunofluorescence analysis of MDA-MB-231 ADAM15A expressing cells showed Claudin-1 at cell-cell junctions, in the cytoplasm and nuclei. ADAM15 co-localised with Claudin-1 and ZO1 at cell-cell junctions. Immunoprecipitation analysis demonstrated complex formation between ADAM15 and ZO1/ZO2. These findings highlight the importance of ADAM15 Intra Cellular Domain-mediated interactions in regulating substrate selection and breast cancer cell phenotype
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