32 research outputs found

    Promoter-bound METTL3 maintains myeloid leukaemia by m6A-dependent translation control.

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    N6-methyladenosine (m6A) is an abundant internal RNA modification in both coding and non-coding RNAs that is catalysed by the METTL3-METTL14 methyltransferase complex. However, the specific role of these enzymes in cancer is still largely unknown. Here we define a pathway that is specific for METTL3 and is implicated in the maintenance of a leukaemic state. We identify METTL3 as an essential gene for growth of acute myeloid leukaemia cells in two distinct genetic screens. Downregulation of METTL3 results in cell cycle arrest, differentiation of leukaemic cells and failure to establish leukaemia in immunodeficient mice. We show that METTL3, independently of METTL14, associates with chromatin and localizes to the transcriptional start sites of active genes. The vast majority of these genes have the CAATT-box binding protein CEBPZ present at the transcriptional start site, and this is required for recruitment of METTL3 to chromatin. Promoter-bound METTL3 induces m6A modification within the coding region of the associated mRNA transcript, and enhances its translation by relieving ribosome stalling. We show that genes regulated by METTL3 in this way are necessary for acute myeloid leukaemia. Together, these data define METTL3 as a regulator of a chromatin-based pathway that is necessary for maintenance of the leukaemic state and identify this enzyme as a potential therapeutic target for acute myeloid leukaemia

    Phenotypes Determined by Cluster Analysis and Their Survival in the Prospective European Scleroderma Trials and Research Cohort of Patients With Systemic Sclerosis

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    Objective: Systemic sclerosis (SSc) is a heterogeneous connective tissue disease that is typically subdivided into limited cutaneous SSc (lcSSc) and diffuse cutaneous SSc (dcSSc) depending on the extent of skin involvement. This subclassification may not capture the entire variability of clinical phenotypes. The European Scleroderma Trials and Research (EUSTAR) database includes data on a prospective cohort of SSc patients from 122 European referral centers. This study was undertaken to perform a cluster analysis of EUSTAR data to distinguish and characterize homogeneous phenotypes without any a priori assumptions, and to examine survival among the clusters obtained. / Methods: A total of 11,318 patients were registered in the EUSTAR database, and 6,927 were included in the study. Twentyā€four clinical and serologic variables were used for clustering. / Results: Clustering analyses provided a first delineation of 2 clusters showing moderate stability. In an exploratory attempt, we further characterized 6 homogeneous groups that differed with regard to their clinical features, autoantibody profile, and mortality. Some groups resembled usual dcSSc or lcSSc prototypes, but others exhibited unique features, such as a majority of lcSSc patients with a high rate of visceral damage and antitopoisomerase antibodies. Prognosis varied among groups and the presence of organ damage markedly impacted survival regardless of cutaneous involvement. / Conclusion: Our findings suggest that restricting subsets of SSc patients to only those based on cutaneous involvement may not capture the complete heterogeneity of the disease. Organ damage and antibody profile should be taken into consideration when individuating homogeneous groups of patients with a distinct prognosis

    Assessing trauma in a transcultural context: challenges in mental health care with immigrants and refugees

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    The growing numbers of refugees and immigrants from conflict-prone areas settling throughout the world bring several challenges for those working in the mental health care system. Immigrants and refugees of all ages arrive with complex and nuanced mental health histories of war, torture, and strenuous migration journeys. Many of the challenges of addressing the health care needs for this growing population of immigrants and refugees are often unfamiliar, and thus practices to address these challenges are not yet routine for care providers and health care organizations. In particular, complex trauma can make mental health assessments difficult for health care organizations or care providers with limited experience and training in transcultural or trauma-informed care. Using a transcultural approach can improve assessment and screening processes, leading to more effective and high-quality care for immigrant and refugee families experiencing mental health disorders. This paper presents findings from an assessment of current mental health services focusing on current practices and experiences with immigrant and refugee patients and families. The difficulties in developing shared understandings about mental health can hinder the therapeutic process; therefore, it is imperative to ensure an effective assessment right from the beginning, yet there is limited use of existing cultural formulation tools from the DSM-IV or DSM-5. The paper outlines current practices, approaches, challenges, and recommendations shared by mental health care providers and program leaders in addressing the mental health care needs of immigrants and refugees. The results from this study demonstrate that there are many challenges and inconsistencies in providing transcultural, trauma-informed care. Respondents emphasized the need for a thorough yet flexible and adaptive approach that allows for an exploration of differences in cultural interpretations of mental health. Our study concluded that ensuring a mindful, reflexive, transcultural, and trauma-informed health care workforce, and a learning environment to support staff with education, resources, and tools will improve the health care experiences of immigrants and refugees in the mental health care system

    Aging affects AO rat splenic conventional dendritic cell subset composition, cytokine synthesis and T-helper polarizing capacity

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    It is well-established that almost all cellular components of innate and adaptive immunity undergo age-related remodelling. The findings on age-related changes in both human and mouse dendritic cells (DCs) are conflicting, whereas there are no data on the influence of aging on rat DCs. In an attempt to fill this gap, freshly isolated splenic DCs expressing CD103 (alpha(OX-62) integrin), a DC specific marker recognized by MRC OX62 monoclonal antibody, from 3- (young) and 26-month-old (aged) Albino Oxford rats were examined for subset composition, expression of activation/differentiation markers (CD80, CD86 and CD40 and MHC II molecules) and endocytic capacity using flow cytometric analysis (FCA). In addition, splenic OX62+ DCs cultured in the presence or absence of LPS were analysed for the activation marker and TNF-alpha, IL-6, IL-12, IL-23, TGF-beta 1, IL-10 expression using FCA, RT-PCR and ELISA, respectively. Moreover, the allostimulatory capacity of OX62+ DCs and IFN-gamma, IL-4 and IL-17 production by CD4+ T cells in mixed leukocyte reaction was quantified using FCA and ELISA, respectively. It was found that aging: i) shifts the CD4+:CD4- subset ratio in the OX62+ DCs population towards the CD4- subset and ii) influences DCs maturation (judging by activation marker expression and efficiency of endocytosis) by affecting the expression of intrinsic (TNF-alpha and IL-10) and extrinsic maturation regulators. Furthermore, in LPS-matured OX62+ DCs from aged rats expression of TNF-alpha, IL-12, IL-23 and IL-6 was increased, whereas that of IL-10 was diminished compared with the corresponding cells from young rats. Moreover, in MLR, OX62+ DCs from aged rats exhibited enhanced Th1/Th17 driving force and diminished allostimulatory capacity compared with those from young rats
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