43 research outputs found

    Apontic regulates somatic stem cell numbers in Drosophila testes

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    BACKGROUND: Microenvironments called niches maintain resident stem cell populations by balancing self-renewal with differentiation, but the genetic regulation of this process is unclear. The niche of the Drosophila testis is well-characterized and genetically tractable, making it ideal for investigating the molecular regulation of stem cell biology. The JAK/STAT pathway, activated by signals from a niche component called the hub, maintains both germline and somatic stem cells. RESULTS: This study investigated the molecular regulation of the JAK/STAT pathway in the stem cells of the Drosophila testis. We determined that the transcriptional regulator Apontic (Apt) acts in the somatic (cyst) stem cells (CySCs) to balance differentiation and maintenance. We found Apt functions as a negative feedback inhibitor of STAT activity, which enables cyst cell maturation. Simultaneous loss of the STAT regulators apt and Socs36E, or the Stat92E-targeting microRNA miR-279, expanded the somatic stem cell-like population. CONCLUSIONS: Genetic analysis revealed that a conserved genetic regulatory network limits JAK/STAT activity in the somatic stem cells of Drosophila testis. In these cells, we determined JAK/STAT signaling promotes apt expression. Then, Apt functions through Socs36E and miR-279 to attenuate pathway activation, which is required for timely CySC differentiation. We propose that Apt acts as a core component of a STAT-regulatory circuit to prevent stem cell overpopulation and allow stem cell maturation

    Therapeutic efficacy of anti-MMP9 antibody in combination with nab-paclitaxel-based chemotherapy in pre-clinical models of pancreatic cancer

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    Matrix metalloproteinase 9 (MMP9) is involved in the proteolysis of extracellular proteins and plays a critical role in pancreatic ductal adenocarcinoma (PDAC) progression, invasion and metastasis. The therapeutic potential of an anti-MMP9 antibody (αMMP9) was evaluated in combination with nab-paclitaxel (NPT)-based standard cytotoxic therapy in pre-clinical models of PDAC. Tumour progression and survival studies were performed in NOD/SCID mice. The mechanistic evaluation involved RNA-Seq, Luminex, IHC and Immunoblot analyses of tumour samples. Median animal survival compared to controls was significantly increased after 2-week therapy with NPT (59%), Gem (29%) and NPT+Gem (76%). Addition of αMMP9 antibody exhibited further extension in survival: NPT+αMMP9 (76%), Gem+αMMP9 (47%) and NPT+Gem+αMMP9 (94%). Six-week maintenance therapy revealed that median animal survival was significantly increased after NPT+Gem (186%) and further improved by the addition of αMMP9 antibody (218%). Qualitative assessment of mice exhibited that αMMP9 therapy led to a reduction in jaundice, bloody ascites and metastatic burden. Anti-MMP9 antibody increased the levels of tumour-associated IL-28 (1.5-fold) and decreased stromal markers (collagen I, αSMA) and the EMT marker vimentin. Subcutaneous tumours revealed low but detectable levels of MMP9 in all therapy groups but no difference in MMP9 expression. Anti-MMP9 antibody monotherapy resulted in more gene expression changes in the mouse stroma compared to the human tumour compartment. These findings suggest that anti-MMP9 antibody can exert specific stroma-directed effects that could be exploited in combination with currently used cytotoxics to improve clinical PDAC therapy

    HLA-DQA1*05 carriage associated with development of anti-drug antibodies to infliximab and adalimumab in patients with Crohn's Disease

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    Anti-tumor necrosis factor (anti-TNF) therapies are the most widely used biologic drugs for treating immune-mediated diseases, but repeated administration can induce the formation of anti-drug antibodies. The ability to identify patients at increased risk for development of anti-drug antibodies would facilitate selection of therapy and use of preventative strategies.This article is freely available via Open Access. Click on Publisher URL to access the full-text

    The genetic architecture of the human cerebral cortex

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    The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

    ReaDAPting the Role of PGRP-SD in Bacterial Sensing and Immune Activation

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    Contradictory to previous reports, Iatsenko et al. (2016) reveal that PGRP-SD regulates the Imd signaling pathway rather than the Toll pathway in Drosophila and shed light on a decade-old mystery of conflicting structural and phenotypic data

    Enabling students to participate in school improvement through a students as researchers programme

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    “The final, definitive version of this article has been published in the Journal Improving Schools, 12 (2), 2009, © SAGE Publications Ltd, 2009: on SAGE Journals Online: http://online.sagepub.com/”This paper explores students’ potential to make a difference to their school through a Students as Researchers programme. It begins by discussing the impetus for the current increase in student voice initiatives in schools. It continues the debate around issues of student empowerment and students’ identity as change agents through an analysis of the development of a Students as Researchers (SAR) programme designed to support school improvement. The article investigates the possibilities for impact offered by a stepped approach to the student research process, early planning for impact and a strong student/teacher partnership. Issues are illuminated though reference to the authors’ work with Students as Researchers groups in several UK schools. The article concludes with an exploration of ways of enhancing the impact of students’ work on the development of their schools.Peer reviewe

    Unique patterns of substance misuse associated with PSTD, depression, and social phobia

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    This study investigated the relations between post-trauma psychopathology and substance abuse in a sample of trauma-exposed college students (N = 136) assigned to four groups based on primary diagnosis: post-traumatic stress disorder (PTSD), depression, social phobia, or well-adjusted (participants who had low levels of distress). Groups were compared on a series of dimensions of substance use/abuse. Participants in the PTSD group evidenced greater substance use and abuse than those in the social phobia and well-adjusted groups on several dimensions and greater alcohol consumption than the depressed group. Correlation analyses suggested that most dimensions of substance abuse were related more strongly to avoidance and numbing (cluster C) symptoms than to re-experiencing and hyperarousal. The present findings suggest that trauma-related psychopathology may be associated with a more hazardous pattern of substance use than depression and social phobia. Copyright © Taylor & Francis Group, LLC
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