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1.
Nucleic Acids Res ; 48(10): 5511-5526, 2020 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-32365184

RESUMO

RNA binding proteins (RBPs) are the primary gene regulators in kinetoplastids as transcriptional control is nearly absent, making Leishmania an exceptional model for investigating methylation of non-histone substrates. Arginine methylation is an evolutionarily conserved protein modification catalyzed by Protein aRginine Methyl Transferases (PRMTs). The chromatin modifier PRMT7 is the only Type III PRMT found in higher eukaryotes and a restricted number of unicellular eukaryotes. In Leishmania major, PRMT7 is a cytoplasmic protein implicit in pathogenesis with unknown substrates. Using comparative methyl-SILAC proteomics for the first time in protozoa, we identified 40 putative targets, including 17 RBPs hypomethylated upon PRMT7 knockout. PRMT7 can modify Alba3 and RBP16 trans-regulators (mammalian RPP25 and YBX2 homologs, respectively) as direct substrates in vitro. The absence of PRMT7 levels in vivo selectively reduces Alba3 mRNA-binding capacity to specific target transcripts and can impact the relative stability of RBP16 in the cytoplasm. RNA immunoprecipitation analyses demonstrate PRMT7-dependent methylation promotes Alba3 association with select target transcripts and thus indirectly stabilizes mRNA of a known virulence factor, δ-amastin surface antigen. These results highlight a novel role for PRMT7-mediated arginine methylation of RBP substrates, suggesting a regulatory pathway controlling gene expression and virulence in Leishmania. This work introduces Leishmania PRMTs as epigenetic regulators of mRNA metabolism with mechanistic insight into the functional manipulation of RBPs by methylation.


Assuntos
Leishmania major/enzimologia , Proteína-Arginina N-Metiltransferases/metabolismo , Proteínas de Protozoários/metabolismo , Proteínas de Ligação a RNA/metabolismo , Regulação da Expressão Gênica , Leishmania major/genética , Metilação , Estabilidade Proteica
2.
Int J Mol Sci ; 22(22)2021 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-34830359

RESUMO

Intracellular trafficking pathways control residency and bioactivity of integral membrane proteins at the cell surface. Upon internalisation, surface cargo proteins can be delivered back to the plasma membrane via endosomal recycling pathways. Recycling is thought to be controlled at the metabolic and transcriptional level, but such mechanisms are not fully understood. In yeast, recycling of surface proteins can be triggered by cargo deubiquitination and a series of molecular factors have been implicated in this trafficking. In this study, we follow up on the observation that many subunits of the Rpd3 lysine deacetylase complex are required for recycling. We validate ten Rpd3-complex subunits in recycling using two distinct assays and developed tools to quantify both. Fluorescently labelled Rpd3 localises to the nucleus and complements recycling defects, which we hypothesised were mediated by modulated expression of Rpd3 target gene(s). Bioinformatics implicated 32 candidates that function downstream of Rpd3, which were over-expressed and assessed for capacity to suppress recycling defects of rpd3∆ cells. This effort yielded three hits: Sit4, Dit1 and Ldb7, which were validated with a lipid dye recycling assay. Additionally, the essential phosphatidylinositol-4-kinase Pik1 was shown to have a role in recycling. We propose recycling is governed by Rpd3 at the transcriptional level via multiple downstream target genes.


Assuntos
Histona Desacetilases/genética , Hidroximetil e Formil Transferases/genética , Proteína Fosfatase 2/genética , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/genética , 1-Fosfatidilinositol 4-Quinase/genética , Membrana Celular/genética , Proteínas Cromossômicas não Histona/genética , Endossomos/genética , Regulação Fúngica da Expressão Gênica/genética , Complexos Multiproteicos/genética , Mapas de Interação de Proteínas/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento
3.
Br J Cancer ; 121(12): 1016-1026, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31673104

RESUMO

BACKGROUND: Phospholipases D1 and D2 (PLD1/2) are implicated in tumorigenesis through their generation of the signalling lipid phosphatidic acid and its downstream effects. Inhibition of PLD1 blocks prostate cell growth and colony formation. Here a role for PLD2 in prostate cancer (PCa), the major cancer of men in the western world, is examined. METHODS: PLD2 expression was analysed by immunohistochemistry and western blotting. The effects of PLD2 inhibition on PCa cell viability and cell motility were measured using MTS, colony forming and wound-healing assays. RESULTS: PLD2 protein is expressed about equally in luminal and basal prostate epithelial cells. In cells from different Gleason-scored PCa tissue PLD2 protein expression is generally higher than in non-tumorigenic cells and increases in PCa tissue scored Gleason 6-8. PLD2 protein is detected in the cytosol and nucleus and had a punctate appearance. In BPH tissue stromal cells as well as basal and luminal cells express PLD2. PLD2 protein co-expresses with chromogranin A in castrate-resistant PCa tissue. PLD2 inhibition reduces PCa cell viability, colony forming ability and directional cell movement. CONCLUSIONS: PLD2 expression correlates with increasing Gleason score to GS8. PLD2 inhibition has the potential to reduce PCa progression.


Assuntos
Carcinogênese/genética , Neoplasias/genética , Fosfolipase D/genética , Neoplasias de Próstata Resistentes à Castração/genética , Proliferação de Células/genética , Sobrevivência Celular/genética , Progressão da Doença , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Gradação de Tumores , Neoplasias/patologia , Neoplasias de Próstata Resistentes à Castração/patologia , Transdução de Sinais/genética
4.
Palliat Med ; 32(10): 1539-1551, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30234421

RESUMO

BACKGROUND: People with advanced heart failure have repeated hospital admissions. Advance care planning can support patient preferences, but studies in people with heart failure have not been assessed. AIM: To evaluate the literature regarding advance care planning in heart failure. DESIGN: Systematic review and narrative analysis (PROSPERO CRD42017059190). DATA SOURCES: Electronic databases were searched (1990 to 23 March 2017): MEDLINE(R), Cochrane Library, CINAHL and Scopus. Four journals were hand searched. Two independent researchers screened against eligibility criteria. One reviewer extracted all data and a sample by a second. Quality was assessed by Cochrane Risk of Bias or the Critical Appraisal Skills Programme Tool for Cohort Studies. RESULTS: Out of the 1713 articles, 8 were included representing 14,357 participants from in/outpatient settings from five countries. Two randomised controlled trials and one observational study assessed planning as part of a specialist palliative care intervention; one randomised controlled trial assessed planning in addition to usual cardiology care; one randomised controlled trial and one observational study assessed planning in an integrated cardiology-palliative care model; one observational study assessed evidence of planning (advance directive) as part of usual care and one observational study was a secondary analysis of trial participants coded Do Not Attempt Cardiopulmonary Resuscitation. Advance care planning: (1) reduced hospitalisation (5/7 studies); (2) increased referral/use of palliative services (4/4 studies); and (3) supported deaths in the patient-preferred place (2/2 studies). CONCLUSION: Advance care planning as part of specialist palliative care reduces hospitalisation. Preliminary studies of planning integrated into generic care, accessing specialist palliative care support if needed, are promising.


Assuntos
Planejamento Antecipado de Cuidados/organização & administração , Insuficiência Cardíaca/terapia , Hospitalização/estatística & dados numéricos , Prestação Integrada de Cuidados de Saúde/organização & administração , Humanos , Narração , Cuidados Paliativos/organização & administração , Qualidade de Vida
5.
Methods ; 82: 38-46, 2015 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-25916617

RESUMO

Flow cytometry is a powerful tool for the quantitation of fluorescence and is proven to be able to correlate the fluorescence intensity to the number of protein on cells surface. Mass spectroscopy can also be used to determine the number of proteins per cell. Here we have developed two methods, using flow cytometry and mass spectroscopy to quantify number of transporters in human cells. These two approaches were then used to analyse the same samples so that a direct comparison could be made. Transporters have a major impact on the behaviour of a diverse number of drugs in human systems. While active uptake studies by transmembrane protein transporters using model substrates are routinely undertaken in human cell lines and hepatocytes as part of drug discovery and development, the interpretation of these results is currently limited by the inability to quantify the number of transporters present in the test samples. Here we provide a flow cytometric method for accurate quantification of transporter levels both on the cell surface and within the cell, and compare this to a quantitative mass spectrometric approach. Two transporters were selected for the study: OATP1B1 (also known as SLCO1B1, LST-1, OATP-C, OATP2) due to its important role in hepatic drug uptake and elimination; P-gp (also known as P-glycoprotein, MDR1, ABCB1) as a well characterised system and due to its potential impact on oral bioavailability, biliary and renal clearance, and brain penetration of drugs that are substrates for this transporter. In all cases the mass spectrometric method gave higher levels than the flow cytometry method. However, the two methods showed very similar trends in the relative ratios of both transporters in the hepatocyte samples investigated. The P-gp antibody allowed quantitative discrimination between externally facing transporters located in the cytoplasmic membrane and the total number of transporters on and in the cell. The proportion of externally facing transporter varied considerably in the four hepatocyte samples analysed, ranging from only 6% to 35% of intact and viable cells. The sample with only 6% externally facing transporter was further analysed by confocal microscopy which qualitatively confirmed the low level of transporter in the membrane and the large internal population. Here we prove that flow cytometry is an important tool for future protein analysis as it can not only quantify the number of proteins that a cell express but also identify the number of proteins on the surface and it is easy to apply for routine assays.


Assuntos
Citometria de Fluxo , Hepatócitos/metabolismo , Espectrometria de Massas , Transportadores de Ânions Orgânicos/análise , Subfamília B de Transportador de Cassetes de Ligação de ATP/análise , Linhagem Celular , Hepatócitos/química , Humanos , Transportador 1 de Ânion Orgânico Específico do Fígado
6.
Plant J ; 75(5): 836-46, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23675613

RESUMO

The RNA-directed DNA methylation (RdDM) pathway is of central importance to the initiation and maintenance of transcriptional gene silencing in plants. DNA methylation is directed to target sequences by a mechanism that involves production of small RNAs by RNA polymerase IV and long non-coding RNAs by RNA polymerase V. DNA methylation then leads to recruitment of histone-modifying enzymes, followed by establishment of a silenced chromatin state. Recently MORC6, a member of the microrchidia (MORC) family of adenosine triphosphatases (ATPases), has been shown to be involved in transcriptional gene silencing. However, reports differ regarding whether MORC6 is involved in RdDM itself or acts downstream of DNA methylation to enable formation of higher-order chromatin structure. Here we demonstrate that MORC6 is required for efficient RdDM at some target loci, and, using a GFP reporter system, we found that morc6 mutants show a stochastic silencing phenotype. By using cell sorting to separate silenced and unsilenced cells, we show that release of silencing at this locus is associated with a loss of DNA methylation. Thus our data support a view that MORC6 influences RdDM and that it is not acting downstream of DNA methylation. For some loci, efficient initiation or maintenance of DNA methylation may depend on the ability to form higher-order chromatin structure.


Assuntos
Adenosina Trifosfatases/fisiologia , Proteínas de Arabidopsis/fisiologia , Arabidopsis/genética , Metilação de DNA , Adenosina Trifosfatases/genética , Adenosina Trifosfatases/metabolismo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Cromossomos de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Mutação , Fenótipo , Regiões Promotoras Genéticas , Análise de Sequência de DNA , Processos Estocásticos
8.
Palliat Med ; 27(9): 822-8, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23838375

RESUMO

BACKGROUND: Heart failure is a common condition with a significant physical and psychological burden for patients and their families. The need for supportive and palliative care: It is well recognised that palliative care is important in patients with advanced heart failure. WHAT IS KNOWN: Heart failure patients have limited access to palliative care services. Barriers to palliative care include difficult prognostication due to the unpredictable disease trajectory and inadequate initiation of conversations about end-of-life care. WHAT IS NOT KNOWN: There are gaps in the evidence for symptom control, especially for symptoms other than pain or dyspnoea, but recommendations are becoming increasingly evidence based. IMPLICATIONS FOR RESEARCH, POLICY AND PRACTICE: There are challenges to research in this area although progress is being made with increasing numbers of trials and use of novel research methods. Integrated models of care based on symptom triggers rather than prognosis are recommended. At the centre is excellent communication both with the patient and between services to ensure the best possible care.


Assuntos
Comunicação , Insuficiência Cardíaca/psicologia , Insuficiência Cardíaca/terapia , Cuidados Paliativos , Dispneia/etiologia , Dispneia/terapia , Pesquisa sobre Serviços de Saúde , Insuficiência Cardíaca/complicações , Humanos , Administração dos Cuidados ao Paciente/métodos , Qualidade de Vida
10.
Mol Biol Cell ; 33(4): ar31, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-35080991

RESUMO

Cell surface protein trafficking is regulated in response to nutrient availability, with multiple pathways directing surface membrane proteins to the lysosome for degradation in response to suboptimal extracellular nutrients. Internalized protein and lipid cargoes recycle back to the surface efficiently in glucose-replete conditions, but this trafficking is attenuated following glucose starvation. We find that cells with either reduced or hyperactive phosphatidylinositol 3-kinase (PI3K) activity are defective for endosome to surface recycling. Furthermore, we find that the yeast Gα subunit Gpa1, an endosomal PI3K effector, is required for surface recycling of cargoes. Following glucose starvation, mRNA and protein levels of a distinct Gα subunit Gpa2 are elevated following nuclear translocation of Mig1, which inhibits recycling of various cargoes. As Gpa1 and Gpa2 interact at the surface where Gpa2 concentrates during glucose starvation, we propose that this disrupts PI3K activity required for recycling, potentially diverting Gpa1 to the surface and interfering with its endosomal role in recycling. In support of this model, glucose starvation and overexpression of Gpa2 alter PI3K endosomal phosphoinositide production. Glucose deprivation therefore triggers a survival mechanism to increase retention of surface cargoes in endosomes and promote their lysosomal degradation.


Assuntos
Fosfatidilinositol 3-Quinase , Proteínas de Saccharomyces cerevisiae , Endossomos/metabolismo , Subunidades alfa de Proteínas de Ligação ao GTP/genética , Subunidades alfa de Proteínas de Ligação ao GTP/metabolismo , Glucose/metabolismo , Proteínas de Membrana/metabolismo , Fosfatidilinositol 3-Quinase/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Transporte Proteico , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo
11.
J Chem Ecol ; 37(3): 311-9, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21340461

RESUMO

We examined how tannin structure influences reactivity in tannin assays and carbon and nitrogen mineralization. Condensed tannins from the foliage of ten tree and shrub species and from pecan shells (Carya illinoensis) had different proportions of: (a) epicatechin (cis) and catechin (trans) isomers, (b) procyanidin (PC) and prodelphinidin (PD) monomers, and (c) different chain lengths. The response of each tannin to several widely used tannin assays was determined. Although there was some variation in response to proanthocyanidin (butanol/HCl) and Folin Ciocalteu assays, we did not deduce any predictable relationship between tannin structure and response to either assay. There was little variation in protein precipitation among the different tannins. To assess biological activity, six of the tannins were incubated with forest humus for 22 days. We determined that, while PC-based tannins remained at least partly extractable for the duration of the incubation, tannins with a high proportion of PD subunits rapidly became unextractable from soil. There was a positive correlation between net nitrogen mineralization and cis chemical structure. Carbon mineralization was enhanced initially by the addition of tannins to humus, but after 22 days, a negative correlation between the proportion of cis subunits and respiration was determined. Overall, we were not able to demonstrate consistent effects of structure on either microbial mineralization or reactivity to chemical assays; such relationships remain elusive.


Assuntos
Proantocianidinas/química , Microbiologia do Solo , Taninos/química , Carbono/metabolismo , Dióxido de Carbono/metabolismo , Isomerismo , Espectroscopia de Ressonância Magnética , Nitrogênio/metabolismo , Ligação Proteica , Taninos/metabolismo
12.
Blood Adv ; 5(23): 4877-4889, 2021 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-34428275

RESUMO

Immune thrombocytopenia (ITP) is an acquired autoimmune condition characterized by both reduced platelet production and the destruction of functionally normal platelets by sustained attack from the immune system. However, the effect of prolonged ITP on the more immature hematopoietic progenitors remains an open area of investigation. By using a murine in vivo model of extended ITP, we revealed that ITP progression drives considerable progenitor expansion and bone marrow (BM) remodeling. Single-cell assays using Lin-Sca1+c-Kit+CD48-CD150+ long-term hematopoietic stem cells (LT-HSCs) revealed elevated LT-HSC activation and proliferation in vitro. However, the increased activation did not come at the expense of LT-HSC functionality as measured by in vivo serial transplantations. ITP progression was associated with considerable BM vasodilation and angiogenesis, as well as a twofold increase in the local production of CXCL12, a cytokine essential for LT-HSC function and BM homing expressed at high levels by LepR+ BM stromal cells. This was associated with a 1.5-fold increase in LepR+ BM stromal cells and a 5.5-fold improvement in progenitor homing to the BM. The increase in stromal cells was transient and reverted back to baseline after platelet count returned to normal, but the vasculature changes in the BM persisted. Together, our data demonstrate that LT-HSCs expand in response to ITP and that LT-HSC functionality during sustained hematopoietic stress is maintained through an adapting BM microenvironment.


Assuntos
Medula Óssea , Púrpura Trombocitopênica Idiopática , Animais , Hematopoese , Células-Tronco Hematopoéticas , Camundongos , Camundongos Endogâmicos C57BL
13.
Dalton Trans ; 49(43): 15219-15230, 2020 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-33021299

RESUMO

We report cytotoxic ruthenium(ii) complexes of the general formula [RuCl(cis-tach)(diphosphine)]+ (cis-tach = cis-cis-1,3,5-triaminocyclohexane) that have been characterised by 1H, 13C and 31P{1H} NMR spectroscopy, mass spectrometry, X-ray crystallography and elemental analysis. The kinetics of aquation and stability of the active species have been studied, showing that the chlorido ligand is substituted by water at 298 K with first order rate constants of 10-2-10-3 s-1, ideal for potential clinical use as anti-tumour agents. Strong interactions with biologically relevant duplex and quadruplex DNA models correlate with the activity observed with A549, A2780 and 293T cell lines, and the degree of activity was found to be sensitive to the chelating diphosphine ligand. A label-free ptychographic cell imaging technique recorded cell death processes over 4 days. The Ru(ii) cis-tach diphosphine complexes exhibit anti-proliferative effects, in some cases outperforming cisplatin and other cytotoxic ruthenium complexes.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Complexos de Coordenação/química , Complexos de Coordenação/farmacologia , DNA/metabolismo , Fosfinas/química , Rutênio/química , Antineoplásicos/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Complexos de Coordenação/metabolismo , Humanos , Cinética , Temperatura
14.
Cardiovasc Res ; 116(1): 12-27, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31386104

RESUMO

Contrary to common perception, modern palliative care (PC) is applicable to all people with an incurable disease, not only cancer. PC is appropriate at every stage of disease progression, when PC needs emerge. These needs can be of physical, emotional, social, or spiritual nature. This document encourages the use of validated assessment tools to recognize such needs and ascertain efficacy of management. PC interventions should be provided alongside cardiologic management. Treating breathlessness is more effective, when cardiologic management is supported by PC interventions. Treating other symptoms like pain or depression requires predominantly PC interventions. Advance Care Planning aims to ensure that the future treatment and care the person receives is concordant with their personal values and goals, even after losing decision-making capacity. It should include also disease specific aspects, such as modification of implantable device activity at the end of life. The Whole Person Care concept describes the inseparability of the physical, emotional, and spiritual dimensions of the human being. Addressing psychological and spiritual needs, together with medical treatment, maintains personal integrity and promotes emotional healing. Most PC concerns can be addressed by the usual care team, supported by a PC specialist if needed. During dying, the persons' needs may change dynamically and intensive PC is often required. Following the death of a person, bereavement services benefit loved ones. The authors conclude that the inclusion of PC within the regular clinical framework for people with heart failure results in a substantial improvement in quality of life as well as comfort and dignity whilst dying.


Assuntos
Planejamento Antecipado de Cuidados/normas , Insuficiência Cardíaca/terapia , Cuidados Paliativos/normas , Planejamento Antecipado de Cuidados/ética , Atitude Frente a Morte , Consenso , Efeitos Psicossociais da Doença , Europa (Continente) , Nível de Saúde , Insuficiência Cardíaca/mortalidade , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/psicologia , Humanos , Saúde Mental , Cuidados Paliativos/ética , Equipe de Assistência ao Paciente , Qualidade de Vida , Resultado do Tratamento
15.
ESC Heart Fail ; 6(6): 1149-1160, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31389157

RESUMO

AIMS: Morphine is shown to relieve chronic breathlessness in chronic obstructive pulmonary disease. There are no definitive data in people with heart failure. We aimed to determine the effectiveness and cost-effectiveness of 12 weeks morphine therapy for the relief of chronic breathlessness in people with chronic heart failure compared with placebo. METHODS AND RESULTS: Parallel group, double-blind, randomized, placebo-controlled, phase III trial of 20 mg daily oral modified release morphine was conducted in 13 sites in England and Scotland: hospital/community cardiology or palliative care outpatients. The primary analysis compared between-group numerical rating scale average breathlessness/24 hours at week 4 using a covariance pattern linear mixed model. Secondary outcomes included treatment-emergent harms (worse or new). The trial closed early due to slow recruitment, randomizing 45 participants [average age 72 (range 39-89) years; 84% men; 98% New York Heart Association class III]. For the primary analysis, the adjusted mean difference was 0.26 (95% confidence interval, -0.86 to 1.37) in favour of placebo. All other breathlessness measures improved in both groups (week 4 change-from-baseline) but by more in those assigned to morphine. Neither group was excessively drowsy at baseline or week 4. There were no between-group differences in quality of life (Kansas) or cognition (Montreal) at any time point. There was no exercise-related desaturation and no change between baseline and week 4 in either group. There was no change in vital signs at week 4. The natriuretic peptide measures fell in both groups but by more in the morphine group [morphine 2169 (1092, 3851) pg/mL vs. placebo 2851 (1694, 5437)] pg/mL. There was no excess serious adverse events in the morphine group. Treatment-emergent harms during the first week were more common in the morphine group; all apart from 1 were ≤ grade 2. CONCLUSIONS: We could not answer our primary objectives due to inadequate power. However, we provide novel placebo-controlled medium-term benefit and safety data useful for clinical practice and future trial design. Morphine should only be prescribed in this population when other measures are unhelpful and with early management of side effects.


Assuntos
Dispneia , Insuficiência Cardíaca/complicações , Morfina , Entorpecentes , Administração Oral , Adulto , Idoso , Idoso de 80 Anos ou mais , Doença Crônica/tratamento farmacológico , Método Duplo-Cego , Dispneia/tratamento farmacológico , Dispneia/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Morfina/administração & dosagem , Morfina/efeitos adversos , Morfina/uso terapêutico , Entorpecentes/administração & dosagem , Entorpecentes/efeitos adversos , Entorpecentes/uso terapêutico
16.
Front Immunol ; 9: 1281, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29930554

RESUMO

Type 1 diabetes (T1D) results from a coordinated autoimmune attack of insulin producing beta cells in the pancreas by the innate and adaptive immune systems, beta cell death being predominantly T cell-mediated. In addition to T cells, peripheral B cells are important in T1D progression. The thymus of mice and man also contains B cells, and lately they have been linked to central tolerance of T cells. The role of thymic B cells in T1D is undefined. Here, we show there are abnormalities in the thymic B cell compartment before beta cell destruction and T1D manifestation. Using non-obese diabetic (NOD) mice, we document that preceding T1D development, there is significant accumulation of thymic B cells-partly through in situ development- and the putative formation of ectopic germinal centers. In addition, in NOD mice we quantify thymic plasma cells and observe in situ binding of immunoglobulins to undefined antigens on a proportion of medullary thymic epithelial cells (mTECs). By contrast, no ectopic germinal centers or pronounced intrathymic autoantibodies are detectable in animals not genetically predisposed to developing T1D. Binding of autoantibodies to thymic stroma correlates with apoptosis of mTECs, including insulin-expressing cells. By contrast, apoptosis of mTECs was decreased by 50% in B cell-deficient NOD mice suggesting intrathymic autoantibodies may selectively target certain mTECs for destruction. Furthermore, we observe that these thymic B cell-associated events correlated with an increased prevalence of premature thymic emigration of T cells. Together, our data suggest that the thymus may be a principal autoimmune target in T1D and contributes to disease progression.


Assuntos
Linfócitos B/imunologia , Citotoxicidade Imunológica , Diabetes Mellitus Tipo 1/etiologia , Células Estromais/imunologia , Timo/imunologia , Animais , Autoimunidade , Linfócitos B/metabolismo , Comunicação Celular/imunologia , Movimento Celular , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/patologia , Progressão da Doença , Feminino , Contagem de Linfócitos , Camundongos , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos Transgênicos , Células Estromais/metabolismo , Linfócitos T/imunologia , Linfócitos T/metabolismo , Timo/metabolismo
17.
Eur J Heart Fail ; 20(9): 1338-1347, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29952090

RESUMO

AIMS: We investigated which patients with heart failure (HF) should receive specialist palliative care (SPC) by first creating a definition of need for SPC in patients hospitalised with HF using patient-reported outcome measures (PROMs) and then testing this definition using the outcome of days alive and out of hospital (DAOH). We also evaluated which baseline variables predicted need for SPC and whether those with this need received SPC. METHODS AND RESULTS: PROMs assessing quality of life (QoL), symptoms, and mood were administered at baseline and every 4 months. SPC need was defined as persistently severe impairment of any PROM without improvement (or severe impairment immediately preceding death). We then tested whether need for SPC, so defined, was reflected in DAOH, a measure which combines length of stay, days of hospital re-admission, and days lost due to death. Of 272 patients recruited, 74 (27%) met the definition of SPC needs. These patients lived one third fewer DAOH than those without SPC need (and less than a quarter of QoL-adjusted DAOH). A Kansas City Cardiomyopathy Questionnaire (KCCQ) summary score of <29 identified patients who subsequently had SPC needs (area under receiver operating characteristic curve 0.78). Twenty-four per cent of patients with SPC needs actually received SPC (n = 18). CONCLUSIONS: A quarter of patients hospitalised with HF had a need for SPC and were identified by a low KCCQ score on admission. Those with SPC need spent many fewer DAOH and their DAOH were of significantly worse quality. Very few patients with SPC needs accessed SPC services.


Assuntos
Insuficiência Cardíaca/terapia , Cuidados Paliativos/estatística & dados numéricos , Medidas de Resultados Relatados pelo Paciente , Seleção de Pacientes , Qualidade de Vida , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/epidemiologia , Hospitalização/estatística & dados numéricos , Humanos , Masculino , Cuidados Paliativos/métodos , Prevalência , Estudos Retrospectivos , Especialização , Reino Unido/epidemiologia
18.
Int J Parasitol ; 37(2): 209-20, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17157855

RESUMO

Infectious cercariae of Schistosoma mansoni gain entry to the mammalian host through the skin where they induce a transient inflammatory influx of mononuclear cells. Some of these cells have antigen-presenting cell function (MHCII+) and have been reported to migrate to the skin-draining lymph nodes (sdLN) where they have the potential to prime CD4+ cells of the acquired immune response. Here, in mice exposed to vaccinating radiation-attenuated schistosome larvae, which induce high levels of protective immunity to challenge infection, we describe the parasite-induced migration of Langerhans cells (LCs) from the epidermal site of immunisation to the sdLN using a specific monoclonal antibody that recognises langerin (CD207). CD207+ cells with dendritic morphology were abundant in the epidermis at all times and their migration into the dermis was detected soon after vaccination. All CD207+ LCs were MHCII+ but not all MHCII+ cells in the skin were CD207+. LCs migrated from the dermis in enhanced numbers after vaccination, as detected in dermal exudate populations recovered after in vitro culture of skin biopsies. Elevated numbers of CD207+ LCs were also detected in the sdLN from 24h to 4 days after vaccination. However, compared with other dermal-derived antigen-presenting cells that were CD207-MHCII+ or CD207-CD11c+, the relative numbers of CD207+ cells in the dermal exudate population and in the sdLN were very small. Furthermore, the migration of CD207+ cells after exposure to 'protective' radiation-attenuated, compared with 'non-protective' normal cercariae, was similar in terms of numbers and kinetics. Together, these studies suggest that CD207+ LCs are only a minor component of the antigen-presenting cell population that migrates from the epidermis and they are unlikely to be important in the priming of protective CD4+ cells in the sdLN.


Assuntos
Antígenos de Superfície/imunologia , Células Epidérmicas , Células de Langerhans/imunologia , Lectinas Tipo C/imunologia , Linfonodos/imunologia , Lectinas de Ligação a Manose/imunologia , Schistosoma mansoni/imunologia , Esquistossomose mansoni/imunologia , Animais , Anticorpos Monoclonais/farmacologia , Derme/citologia , Feminino , Imunofenotipagem , Camundongos , Camundongos Endogâmicos C57BL
19.
Am Heart J ; 151(6): 1313-21, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16781243

RESUMO

BACKGROUND: Anemia is an adverse prognostic marker in heart failure (HF), but its cause and relationships with other comorbidities are uncertain. METHODS: All index emergency HF admissions to one urban hospital during the year 2000 were studied. RESULTS: Of 528 consecutive admissions with HF, 45% of patients (51% men and 38% women) had anemia (Hb <13 g/dL in men and <11.5 in women), which was usually normocytic. Anemia was equally common in patients with reduced and preserved systolic function. Hematinic deficiencies were rare, but 162 (70%) of anemic patients were lymphopenic. Median (interquartile range) C-reactive protein was higher in anemic patients compared with nonanemic patients (21 [5-211] mg/L vs 13 [5-155] mg/L, P = .0086). Marked reductions in glomerular filtration rate (<30 mL/min per 1.73m(2)) were more common in anemic patients (24%) than nonanemic patients (9%) (P < .0001). Median follow-up was 814 days (range 632-978 days). One hundred twenty-five (54%) anemic patients died, compared with 93 (32%) nonanemic patients (P < .00001), and anemia was a predictor of death (in patients with reduced or preserved systolic function) and death or hospital readmission. CONCLUSIONS: Renal dysfunction is one probable cause of anemia in HF. The overlap of anemia and lymphopenia suggest that hematopoiesis may be more generally depressed. Anemia is a predictor of adverse outcome in HF, irrespective of systolic function.


Assuntos
Anemia/complicações , Anemia/epidemiologia , Insuficiência Cardíaca/complicações , Idoso , Feminino , Insuficiência Cardíaca/mortalidade , Humanos , Masculino , Prevalência , Fatores de Risco
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