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The Congenital Dyserythropoietic Anemia (CDA) Registry was established with the goal to facilitate investigations of natural history, biology, and molecular pathogenetic mechanisms of CDA. Three unrelated individuals enrolled in the registry had a syndrome characterized by CDA and severe neurodevelopmental delay. They were found to have missense mutations in VPS4A, a gene coding for an ATPase that regulates the ESCRT-III machinery in a variety of cellular processes including cell division, endosomal vesicle trafficking, and viral budding. Bone marrow studies showed binucleated erythroblasts and erythroblasts with cytoplasmic bridges indicating abnormal cytokinesis and abscission. Circulating red blood cells were found to retain transferrin receptor (CD71) in their membrane, demonstrating that VPS4A is critical for normal reticulocyte maturation. Using proband-derived induced pluripotent stem cells (iPSCs), we have successfully modeled the hematologic aspects of this syndrome in vitro, recapitulating their dyserythropoietic phenotype. Our findings demonstrate that VPS4A mutations cause cytokinesis and trafficking defects leading to a human disease with detrimental effects to erythropoiesis and neurodevelopment.
Assuntos
ATPases Associadas a Diversas Atividades Celulares/genética , Anemia Diseritropoética Congênita/genética , Complexos Endossomais de Distribuição Requeridos para Transporte/genética , ATPases Vacuolares Próton-Translocadoras/genética , Adenosina Trifosfatases/metabolismo , Anemia Diseritropoética Congênita/patologia , Medula Óssea/patologia , Células da Medula Óssea/metabolismo , Criança , Pré-Escolar , Citocinese , Endossomos/metabolismo , Eritroblastos/metabolismo , Eritrócitos/citologia , Eritropoese , Feminino , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Masculino , Transtornos do Neurodesenvolvimento/metabolismo , Fenótipo , Transporte Proteico , Reticulócitos/citologiaRESUMO
Hereditary neutropenia is usually caused by heterozygous germline mutations in the ELANE gene encoding neutrophil elastase (NE). How mutations cause disease remains uncertain, but two hypotheses have been proposed. In one, ELANE mutations lead to mislocalization of NE. In the other, ELANE mutations disturb protein folding, inducing an unfolded protein response in the endoplasmic reticulum (ER). In this study, we describe new types of mutations that disrupt the translational start site. At first glance, they should block translation and are incompatible with either the mislocalization or misfolding hypotheses, which require mutant protein for pathogenicity. We find that start-site mutations, instead, force translation from downstream in-frame initiation codons, yielding amino-terminally truncated isoforms lacking ER-localizing (pre) and zymogen-maintaining (pro) sequences, yet retain essential catalytic residues. Patient-derived induced pluripotent stem cells recapitulate hematopoietic and molecular phenotypes. Expression of the amino-terminally deleted isoforms in vitro reduces myeloid cell clonogenic capacity. We define an internal ribosome entry site (IRES) within ELANE and demonstrate that adjacent mutations modulate IRES activity, independently of protein-coding sequence alterations. Some ELANE mutations, therefore, appear to cause neutropenia via the production of amino-terminally deleted NE isoforms rather than by altering the coding sequence of the full-length protein.
Assuntos
Elastase de Leucócito/genética , Elastase de Leucócito/metabolismo , Mutação , Neutropenia/metabolismo , Biossíntese de Proteínas , Apoptose , Códon , Análise Mutacional de DNA , Retículo Endoplasmático/metabolismo , Células HL-60 , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Neutrófilos/citologia , Fenótipo , Desnaturação Proteica , Dobramento de Proteína , Isoformas de Proteínas/metabolismo , Células U937RESUMO
Our knowledge of the molecular mechanisms underlying human embryonic stem cell (hESC) self-renewal and differentiation is incomplete. The level of octamer-binding transcription factor 4 (Oct4), a critical regulator of pluripotency, is precisely controlled in mouse embryonic stem cells. However, studies of human OCT4 are often confounded by the presence of three isoforms and six expressed pseudogenes, which has complicated the interpretation of results. Using an inducible lentiviral overexpression and knockdown system to manipulate OCT4A above or below physiological levels, we specifically examine the functional role of the OCT4A isoform in hESC. (We also designed and generated a comparable series of vectors, which were not functional, for the overexpression and knockdown of OCT4B.) We show that specific knockdown of OCT4A results in hESC differentiation, as indicated by morphology changes, cell surface antigen expression, and upregulation of ectodermal genes. In contrast, inducible overexpression of OCT4A in hESC leads to a transient instability of the hESC phenotype, as indicated by changes in morphology, cell surface antigen expression, and transcriptional profile, that returns to baseline within 5 days. Interestingly, sustained expression of OCT4A past 5 days enhances hESC cloning efficiency, suggesting that higher levels of OCT4A can support self-renewal. Overall, our results indicate that high levels of OCT4A increase hESC cloning efficiency and do not induce differentiation (whereas OCT4B expression cannot be induced in hESC), highlighting the importance of isoform-specific studies in a stable and inducible expression system for human OCT4. Additionally, we demonstrate the utility of an efficient method for conditional gene expression in hESC.
Assuntos
Células Clonais/metabolismo , Células-Tronco Embrionárias/metabolismo , Fator 3 de Transcrição de Octâmero/biossíntese , Isoformas de Proteínas/biossíntese , Animais , Diferenciação Celular/genética , Células Clonais/citologia , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Camundongos , Células-Tronco Pluripotentes , RNA Mensageiro/biossíntese , RNA Mensageiro/genéticaRESUMO
Bacterial and fungal infections are a major cause of morbidity and mortality in neutropenic patients. Donor-derived neutrophil transfusions have been used for prophylaxis or treatment for infection in neutropenic patients. However, the short half-life and the limited availability of large numbers of donor-derived neutrophils for transfusion remain a significant hurdle in the implementation of neutrophil transfusion therapy. Here, we investigate the in vitro and in vivo activity of neutrophils generated from human induced pluripotent stem cells (iPSC), a potentially unlimited resource to produce neutrophils for transfusion. Phenotypic analysis of iPSC-derived neutrophils reveal reactive oxygen species production at similar or slightly higher than normal peripheral blood neutrophils, but have an â¼50%-70% reduced Escherichia coli phagocytosis and phorbol 12-myristate 13-acetate induced formation of neutrophil extracellular traps (NET). Signaling of granulocytic precursors identified impaired AKT activation, but not ERK or STAT3, in agonist-stimulated iPSC-derived neutrophils. Expression of a constitutively activated AKT in iPSC-derived neutrophils restores most phagocytic activity and NET formation. In a model of bacterial induced peritonitis in immunodeficient mice, iPSC-derived neutrophils, with or without corrected AKT activation, migrate similarly to the peritoneal fluid as peripheral blood neutrophils, whereas the expression of activated AKT significantly improves their phagocytic activity in vivo. Stem Cells Translational Medicine 2019;8:557-567.
Assuntos
Neutrófilos/imunologia , Fagocitose , Adulto , Animais , Escherichia coli/patogenicidade , Armadilhas Extracelulares/efeitos dos fármacos , Armadilhas Extracelulares/metabolismo , Feminino , Fator Estimulador de Colônias de Granulócitos/farmacologia , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Masculino , Camundongos , Neutrófilos/citologia , Neutrófilos/metabolismo , Neutrófilos/transplante , Peritonite/patologia , Peritonite/terapia , Proteínas Proto-Oncogênicas c-akt/agonistas , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Acetato de Tetradecanoilforbol/farmacologiaRESUMO
INTRODUCTION: Spousal support is one of the strongest and most consistent predictors of Type 2 diabetes treatment adherence. However, the effects of both spouses' evaluations of dyadic coping on emotional distress and patients' physical health remain largely unknown. METHOD: Dyadic data from 117 married couples in which one member is diagnosed with Type 2 diabetes were evaluated in two separate models to explore the associations between (a) patients' and spouses' depression symptoms and patients' adherence to dietary and exercise regimens, and (b) patients' and spouses' acute stress levels and patients' adherence to dietary and exercise regimens. Finally, evaluative dyadic coping was included as a possible moderator between these associations. RESULTS: Results from an actor-partner interdependence model revealed significant actor effects of patients' depression symptoms on patients' adherence to dietary and exercise regimens. Spouses' evaluation of dyadic coping attenuated the direct paths between spouses' depression symptoms and patients' adherence to dietary regimens. No direct pathways were found from patients' or spouses' acute stress to patients' adherence to dietary and exercise regimens. However, spouses' evaluation of dyadic coping attenuated the direct paths between spouses' acute stress and patients' adherence to dietary regimens. DISCUSSION: Tapping into spouses' evaluations of dyadic coping has significant implications for patients' diabetes health outcomes (e.g., adherence to dietary and exercise treatment regimens). Findings from this study highlight the need for systemic interventions targeting both partners. (PsycINFO Database Record
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Adaptação Psicológica , Diabetes Mellitus Tipo 2/psicologia , Estresse Psicológico/psicologia , Cooperação e Adesão ao Tratamento/psicologia , Idoso , Depressão/etiologia , Depressão/psicologia , Diabetes Mellitus Tipo 2/complicações , Feminino , Humanos , Relações Interpessoais , Masculino , Pessoa de Meia-Idade , Psicometria/instrumentação , Psicometria/métodos , Estresse Psicológico/etiologia , Inquéritos e QuestionáriosRESUMO
INTRODUCTION: Cardiovascular disease (CVD) is the leading cause of death for both men and women. Its potential ramifications on all aspects of life, for patients and partners, are just beginning to be understood. Although research has focused on the individual who has received the diagnosis, relatively little is known about how couples manage CVD. This article presents a systematic review of literature that focuses on how couples cope with one partner's CVD diagnosis. A systematic review is warranted to orient practitioners, policy makers, and researchers to the state of existing knowledge and its gaps and to identify what still needs to be done. METHOD: Data were extracted from 25 peer-reviewed articles that met our inclusion criteria. Content examined included theory integration, coping constructs and instruments, samples, analyses, and findings. RESULTS: Most articles successfully integrated theory in the studies' respective conceptualizations and designs. Most used valid and reliable instruments to measure coping. Principal limitations included problematic sampling strategies and analysis techniques, thereby limiting external validity. DISCUSSION: Principal implications of this review's findings relate to our fields' need to provide more care focused on dyads (vs. individual patients), adopt an integrated model in health care, and conduct systemic, longitudinal research to gain a better grasp on how coping changes over time. Doing so will serve to better equip providers in the support of patients and partners living with CVD. (PsycINFO Database Record
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Adaptação Psicológica , Doenças Cardiovasculares/psicologia , Características da Família , Doenças Cardiovasculares/complicações , HumanosRESUMO
INTRODUCTION: Maintaining optimal self-care in managing Type 2 diabetes is a common struggle for patients due to several barriers, including access to quality services, financial insecurity and/or lack of insurance, and emotional distress. Consequently, morbidity and mortality rates are high, alongside rising health care costs. Alternative approaches that address common barriers require further investigation. This systematic review of randomized controlled trials examines the effectiveness of using community health workers (CHWs) in Type 2 diabetes care. This effort is warranted to orient practitioners and researchers to the state of existing knowledge, and to direct clinical practice and future research. METHOD: Data were extracted from 17 peer-reviewed articles; they were examined with respect to theory integration, CHW intervention design, outcome variables, and findings. RESULTS: Approximately one-third of articles explicitly integrated theory into their research conceptualization and design. There was great variation across intervention dosages, attrition rates, and methods of CHW training. Main foci across studies' findings suggest that a CHW intervention has significant impacts on physical health outcomes, diabetes knowledge, self-care behaviors, and emotional distress and well-being. DISCUSSION: Principal implications relate to the need for more research regarding CHW intervention types and methods, and further investigation about the mechanisms of change within a CHW-delivered intervention. Findings support the case for more CHWs in treatment teams to bridge patients with the medical system. This research will serve to better equip providers in the support of patients managing Type 2 diabetes and advance the Triple Aim of health care. (PsycINFO Database Record
Assuntos
Agentes Comunitários de Saúde , Diabetes Mellitus Tipo 2/terapia , Papel Profissional , Doença Crônica/terapia , Humanos , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
College women are vulnerable to depression due to developmental and transitional life changes. Early diagnosis and effective treatment is critically important. Empirical support exists for the effectiveness of select treatment options (i.e., antidepressant medication, cognitive-behavioral therapy [CBT], and interpersonal psychotherapy [IPT]), yet a significant percentage of those treated do not benefit. In this pilot study, Internal Family Systems (IFS) therapy was tested as an alternative approach. College women (N = 37) were randomly allocated to IFS treatment or treatment as usual (CBT or IPT). Results demonstrated a decline in depressive symptoms for both conditions and no significant differences in the magnitude or rate of change. The results provide preliminary evidence for the efficacy of IFS in the treatment of depressive symptoms.
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Depressão/terapia , Avaliação de Resultados em Cuidados de Saúde , Psicoterapia/métodos , Estudantes/psicologia , Adolescente , Adulto , Terapia Cognitivo-Comportamental/métodos , Feminino , Humanos , Relações Interpessoais , Projetos Piloto , Universidades , Adulto JovemRESUMO
INTRODUCTION: Research examining the implementation and effectiveness of integrated behavioral health (BH) care in family medicine/primary care is growing. However, research identifying ways to consistently use integrated BH in busy family medicine/primary care settings with underserved populations is limited. This study describes 1 family medicine clinic's transformation into a fully integrated BH care clinic through the development of an Integrated Care Clinic (ICC) and enhanced clinical pathways to promote regular use of behavioral health clinicians (BHCs). METHOD: We implemented the ICC at the Broadway Family Medicine Clinic serving a low-income (<$25,000 annual income/year) and minority population (>70% African American) in Minnesota. We conducted a pre- and postevaluation of the ICC during regular clinic activity. RESULTS: Pilot findings indicated that the creation of ICC and the use of enhanced clinical pathways (e.g., 5-2-1-0 obesity prevention messages, Transitional Care Management, postpartum depression screening visits, warm hand-offs) to facilitate regular use of integrated BH care resulted in 6 integrated care visits per BHC per clinic half-day. In addition, changes in the behavioral/mental health therapy appointment time slot (from 60 to 30 min) reduced therapy no-show rates. Transitional Care Management (TCM) visits also showed improved pre- and postchanges in patient and clinician satisfaction and reductions in patient hospital readmission rates. DISCUSSION: The transformation into a fully integrated BH family medicine clinic through the creation of ICC and enhanced clinical pathways to facilitate regular integrated BH care showed promising pilot results. Future research is needed to examine associations between ICC and patient outcomes (e.g., weight, depressive symptoms). (PsycINFO Database Record
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Medicina do Comportamento/métodos , Procedimentos Clínicos , Prestação Integrada de Cuidados de Saúde/métodos , Saúde da Família/tendências , Instituições de Assistência Ambulatorial/organização & administração , Instituições de Assistência Ambulatorial/tendências , Agendamento de Consultas , Terapia Comportamental/métodos , Saúde da Família/etnologia , Acessibilidade aos Serviços de Saúde/normas , Acessibilidade aos Serviços de Saúde/estatística & dados numéricos , Humanos , Minnesota/etnologia , Grupos Minoritários , Pobreza/etnologiaRESUMO
Severe congenital neutropenia (SCN) is often associated with inherited heterozygous point mutations in ELANE, which encodes neutrophil elastase (NE). However, a lack of appropriate models to recapitulate SCN has substantially hampered the understanding of the genetic etiology and pathobiology of this disease. To this end, we generated both normal and SCN patient-derived induced pluripotent stem cells (iPSCs), and performed genome editing and differentiation protocols that recapitulate the major features of granulopoiesis. Pathogenesis of ELANE point mutations was the result of promyelocyte death and differentiation arrest, and was associated with NE mislocalization and activation of the unfolded protein response/ER stress (UPR/ER stress). Similarly, high-dose G-CSF (or downstream signaling through AKT/BCL2) rescues the dysgranulopoietic defect in SCN patient-derived iPSCs through C/EBPß-dependent emergency granulopoiesis. In contrast, sivelestat, an NE-specific small-molecule inhibitor, corrected dysgranulopoiesis by restoring normal intracellular NE localization in primary granules; ameliorating UPR/ER stress; increasing expression of CEBPA, but not CEBPB; and promoting promyelocyte survival and differentiation. Together, these data suggest that SCN disease pathogenesis includes NE mislocalization, which in turn triggers dysfunctional survival signaling and UPR/ER stress. This paradigm has the potential to be clinically exploited to achieve therapeutic responses using lower doses of G-CSF combined with targeting to correct NE mislocalization.
Assuntos
Doenças Genéticas Inatas , Células-Tronco Pluripotentes Induzidas/enzimologia , Elastase de Leucócito , Mielopoese/genética , Neutropenia , Neutrófilos/enzimologia , Mutação Puntual , Proteína beta Intensificadora de Ligação a CCAAT/genética , Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Proteínas Estimuladoras de Ligação a CCAAT/genética , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Células Cultivadas , Estresse do Retículo Endoplasmático/genética , Feminino , Doenças Genéticas Inatas/enzimologia , Doenças Genéticas Inatas/genética , Fator Estimulador de Colônias de Granulócitos/farmacologia , Células Precursoras de Granulócitos/enzimologia , Humanos , Elastase de Leucócito/genética , Elastase de Leucócito/metabolismo , Masculino , Resposta a Proteínas não Dobradas/genéticaRESUMO
Diffusion of autocrine and paracrine signaling molecules allows cells to communicate in the absence of physical contact. This chemical-based, long-range communication serves crucial roles in tissue function, activation of the immune system, and other physiological functions. Despite its importance, few in vitro methods to study cell-cell signaling through paracrine factors are available today. Here, we report the design and validation of a microfluidic platform that enables (i) soluble molecule-cell and/or (ii) cell-cell paracrine signaling. In the microfluidic platform, multiple cell populations can be introduced into parallel channels. The channels are separated by arrays of posts allowing diffusion of paracrine molecules between cell populations. A computational analysis was performed to aid design of the microfluidic platform. Specifically, it revealed that channel spacing affects both spatial and temporal distribution of signaling molecules, while the initial concentration of the signaling molecule mainly affects the concentration of the signaling molecules excreted by the cells. To validate the microfluidic platform, a model system composed of the signaling molecule lipopolysaccharide, mouse macrophages, and engineered human embryonic kidney cells was introduced into the platform. Upon diffusion from the first channel to the second channel, lipopolysaccharide activates the macrophages which begin to produce TNF-α. The TNF-α diffuses from the second channel to the third channel to stimulate the kidney cells, which express green fluorescent protein (GFP) in response. By increasing the initial lipopolysaccharide concentration an increase in fluorescent response was recorded, demonstrating the ability to quantify intercellular communication between 3D cellular constructs using the microfluidic platform reported here. Overall, these studies provide a detailed analysis on how concentration of the initial signaling molecules, spatiotemporal dynamics, and inter-channel spacing affect intercellular communication.
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Despite the potential benefits of selective redox-modulating strategies for cancer therapy, an efficacious methodology for testing therapies remains elusive because of the difficulty in measuring intracellular redox potentials over time. In this report, we have incorporated a new FRET-based biosensor to follow in real time redox-sensitive processes in cells transformed to be tumorigenic and cultured in a microfluidic channel. A microfluidic network was used to control micro-scale flow near the cells and at the same time deliver drugs exogenously. Subsequently, the response of a redox homeostasis circuit was tested, namely reduced glutathione (GSH)/oxidized glutathione(GSSG), to diamide, a thiol oxidant, and two drugs used for cancer therapies: BSO (L-buthionine-[SR]-sulfoximine) and BCNU (carmustine). The main outcome from these experiments is a comparison of the temporal depletion and recovery of GSH in single living cells in real-time. These data demonstrate that mammalian cells are capable of restoring a reduced intracellular redox environment in minutes after an acute oxidative insult is removed. This recovery is significantly delayed by (i) the inhibition of GSH biosynthesis by BSO; (ii) the inactivation of glutathione reductase by BCNU; and (iii) in tumorigenic cells relative to an isogenic non-tumorigenic control cell line.