Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 74
Filtrar
1.
J Holist Nurs ; 40(2): 99-107, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34125628

RESUMO

Purpose of Study: The purpose of the study was to evaluate the usefulness of the aromatherapy (AT) recommendation in the American Holistic Nurses Association's (AHNA's) Holistic Nurses' Pain Relief Tools for Patients and Self-Care (Pain Tool). Methodology: An observational survey design was used and a purposeful sample of 55 nurses were invited to a two-part, 15-question survey administered via SurveyMonkey. The demographic data were analyzed with quantitative analysis and the open-ended questions were analyzed via content analysis. Results: A total of 55 registered nurses completed the survey and the mean age of participants was 53 years old. Lavender essential oil (EO) was used by 100% (N = 55) of participants and the inhalation method was favored (93%; n = 51). The AT recommendation was most helpful for educational purposes (29%; n = 16) and to reduce symptoms of pain (21%; n = 8). A majority of participants used the five holistic nursing core values (70%; n = 31) as well as promote more options for pain management (48%; n = 13) to improve outcomes (30%; n = 13). Respondents recommend the addition of more EOs and safety information (23%; n = 8). Finally, five recommendations were made to AHNA. Implication for Practice: Nurses who use AT (guideline) as a safe, cost-effective intervention for pain improve quality outcomes.


Assuntos
Aromaterapia , Enfermeiras e Enfermeiros , Óleos Voláteis , Humanos , Pessoa de Meia-Idade , Óleos Voláteis/uso terapêutico , Dor , Manejo da Dor/métodos , Autocuidado
2.
Proc Natl Acad Sci U S A ; 117(22): 12230-12238, 2020 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-32414920

RESUMO

Tibetans have adapted to the chronic hypoxia of high altitude and display a distinctive suite of physiologic adaptations, including augmented hypoxic ventilatory response and resistance to pulmonary hypertension. Genome-wide studies have consistently identified compelling genetic signatures of natural selection in two genes of the Hypoxia Inducible Factor pathway, PHD2 and HIF2A The product of the former induces the degradation of the product of the latter. Key issues regarding Tibetan PHD2 are whether it is a gain-of-function or loss-of-function allele, and how it might contribute to high-altitude adaptation. Tibetan PHD2 possesses two amino acid changes, D4E and C127S. We previously showed that in vitro, Tibetan PHD2 is defective in its interaction with p23, a cochaperone of the HSP90 pathway, and we proposed that Tibetan PHD2 is a loss-of-function allele. Here, we report that additional PHD2 mutations at or near Asp-4 or Cys-127 impair interaction with p23 in vitro. We find that mice with the Tibetan Phd2 allele display augmented hypoxic ventilatory response, supporting this loss-of-function proposal. This is phenocopied by mice with a mutation in p23 that abrogates the PHD2:p23 interaction. Hif2a haploinsufficiency, but not the Tibetan Phd2 allele, ameliorates hypoxia-induced increases in right ventricular systolic pressure. The Tibetan Phd2 allele is not associated with hemoglobin levels in mice. We propose that Tibetans possess genetic alterations that both activate and inhibit selective outputs of the HIF pathway to facilitate successful adaptation to the chronic hypoxia of high altitude.


Assuntos
Adaptação Fisiológica , Proteínas de Ligação a DNA/metabolismo , Prolina Dioxigenases do Fator Induzível por Hipóxia/genética , Prolina Dioxigenases do Fator Induzível por Hipóxia/metabolismo , Prolina Dioxigenases do Fator Induzível por Hipóxia/fisiologia , Hipóxia/fisiopatologia , Mutação com Perda de Função , Alelos , Altitude , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Proteínas de Ligação a DNA/genética , Humanos , Camundongos , Camundongos Knockout , Fenótipo , Seleção Genética , Tibet
3.
Ann Hematol ; 98(5): 1111-1118, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30535576

RESUMO

External quality assurance (EQA) programs are vital to ensure high quality and standardized results in molecular diagnostics. It is important that EQA for quantitative analysis takes into account the variation in methodology. Results cannot be expected to be more accurate than limits of the technology used, and it is essential to recognize factors causing substantial outlier results. The present study aimed to identify parameters of specific importance for JAK2 V617F quantification by quantitative PCR, using different starting materials, assays, and technical platforms. Sixteen samples were issued to participating laboratories in two EQA rounds. In the first round, 19 laboratories from 11 European countries analyzing JAK2 V617F as part of their routine diagnostics returned results from in-house assays. In the second round, 25 laboratories from 17 countries participated. Despite variations in starting material, assay set-up and instrumentation the laboratories were generally well aligned in the EQA program. However, EQA based on a single technology appears to be a valuable tool to achieve standardization of the quantification of JAK2 V617F allelic burden.


Assuntos
Janus Quinase 2/genética , Mutação de Sentido Incorreto , Patologia Molecular/normas , Garantia da Qualidade dos Cuidados de Saúde , Reação em Cadeia da Polimerase em Tempo Real/normas , Substituição de Aminoácidos , Feminino , Humanos , Masculino
4.
BMC Cancer ; 18(1): 286, 2018 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-29534684

RESUMO

BACKGROUND: The role of the hypoxia signaling pathway in the pathogenesis of pheochromocytoma/paraganglioma (PPGL)-polycythemia syndrome has been elucidated. Novel somatic mutations in hypoxia-inducible factor type 2A (HIF2A) and germline mutations in prolyl hydroxylase type 1 and type 2 (PHD1 and PHD2) have been identified to cause upregulation of the hypoxia signaling pathway and its target genes including erythropoietin (EPO) and its receptor (EPOR). However, in a minority of patients presenting with this syndrome, the genetics and molecular pathogenesis remain unexplained. The aim of the present study was to uncover novel genetic causes of PPGL-polycythemia syndrome. CASE PRESENTATION: A female presented with a history of JAK2V617F positive PV, diagnosed in 2007, and right adrenal pheochromocytoma diagnosed and resected in 2011. Her polycythemia symptoms and hematocrit levels continued to worsen from 2007 to 2011, with an increased frequency of phlebotomies. Postoperatively, until early 2013, her hematocrit levels remained normalized. Following this, the hematocrit levels ranged between 46.4 and 48.9% [35-45%]. Tumor tissue from the patient was further tested for mutations in genes related to upregulation of the hypoxia signaling pathway including iron regulatory protein 1 (IRP1), which is a known regulator of HIF-2α mRNA translation. Functional studies were performed to investigate the consequences of these mutations, especially their effect on the HIF signaling pathway and EPO. Indel mutations (c.267-1_267delGGinsTA) were discovered at the exon 3 splicing site of IRP1. Minigene construct and splicing site analysis showed that the mutation led to a new splicing site and a frameshift mutation of IRP1, which caused a truncated protein. Fluorescence in situ hybridization analysis demonstrated heterozygous IRP1 deletions in tumor cells. Immunohistochemistry results confirmed the truncated IRP1 and overexpressed HIF-2α, EPO and EPOR in tumor cells. CONCLUSIONS: This is the first report which provides direct molecular genetic evidence of association between a somatic IRP1 loss-of-function mutation and PHEO and secondary polycythemia. In patients diagnosed with PHEO/PGL and polycythemia with negative genetic testing for mutations in HIF2A, PHD1/2, and VHL, IRP1 should be considered as a candidate gene.


Assuntos
Neoplasias das Glândulas Suprarrenais/genética , Mutação em Linhagem Germinativa , Proteína 1 Reguladora do Ferro/genética , Janus Quinase 2/genética , Feocromocitoma/genética , Policitemia Vera/genética , Splicing de RNA , Neoplasias das Glândulas Suprarrenais/complicações , Neoplasias das Glândulas Suprarrenais/patologia , Adulto , Feminino , Humanos , Feocromocitoma/complicações , Feocromocitoma/patologia , Policitemia Vera/complicações , Policitemia Vera/patologia , Prognóstico
5.
Genet Test Mol Biomarkers ; 22(2): 98-103, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29323541

RESUMO

BACKGROUND: The classical Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs), consisting of polycythemia vera, essential thrombocythemia, and primary myelofibrosis, are a heterogeneous group of neoplasms that harbor driver mutations in the JAK2, CALR, and MPL genes. The detection of mutations in these genes has been incorporated into the recent World Health Organization (WHO) diagnostic criteria for MPN. Given a pressing clinical need to screen for mutations in these genes in a routine diagnostic setting, a targeted next-generation sequencing (NGS) assay for the detection of MPN-associated mutations located in JAK2 exon 14, JAK2 exon 12, CALR exon 9, and MPL exon 10 was developed to provide a single platform alternative to reflexive, stepwise diagnostic algorithms. METHODS: Polymerase chain reaction (PCR) primers were designed to target mutation hotspots in JAK2 exon 14, JAK2 exon 12, MPL exon 10, and CALR exon 9. Multiplexed PCR conditions were optimized by using qualitative PCR followed by NGS. Diagnostic genomic DNA from 35 MPN patients, known to harbor driver mutations in one of the target genes, was used to validate the assay. RESULTS: One hundred percent concordance was observed between the previously-identified mutations and those detected by NGS, with no false positives, nor any known mutations missed (specificity = 100%, CI = 0.96, sensitivity = 100%, CI = 0.89). Improved resolution of mutation sequences was also revealed by NGS analysis. CONCLUSION: Detection of diagnostically relevant driver mutations of MPN is enhanced by employing a targeted multiplex NGS approach. This assay presents a robust solution to classical MPN mutation screening, providing an alternative to time-consuming sequential analyses.


Assuntos
Calreticulina/genética , Análise Mutacional de DNA/métodos , Janus Quinase 2/genética , Transtornos Mieloproliferativos/genética , Receptores de Trombopoetina/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Reação em Cadeia da Polimerase
6.
J Clin Pathol ; 70(8): 662-668, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28143941

RESUMO

AIMS: Somatic insertions/deletions in exon 9 of the calreticulin gene have been identified in patients with essential thrombocythemia and primary myelofibrosis. Over 55 mutations have been discovered, 80% of which consist of either type 1 52-bp deletion or type 2 5-bp insertion. Other mutations (types 3-5) in conjunction with types 1 and 2 account for >87% of identified mutations. The aim of this study was development of a rapid PCR-based assay using LightCycler Hybridisation Probes for the detection of type 1-5 CALR mutations. METHOD: A real-time PCR assay using a novel HybProbe set was developed for use on the LightCycler 480 Instrument II. The acceptor probe was labelled with LC640 and Faststart DNA Master HybProbe kit was used for PCR reactions. RESULTS: Assay limit of detection was determined to be seven target copies with a probability of 95%. The specificity of the assay was determined by using synthetic constructs of CALR wild-type and CALR mutation types 1-5 with no non-specific detection observed. Samples from 21 patients with essential thrombocythemia (ET) and 12 patients with primary myelofibrosis (PMF), together with 29 control samples from patients diagnosed with various conditions, were screened using the assay. Of these, 24 were found to have mutations in CALR exon 9, with the assay detecting 8 type 1 mutations, 12 type 2 mutations, 2 type 24 mutations, 1 type 20 mutation and 1 31-bp deletion. CONCLUSIONS: The novel assay described has potential for application as a rapid, sensitive, high-throughput screening method in the clinical diagnostics setting.


Assuntos
Calreticulina/genética , Éxons/genética , Ensaios de Triagem em Larga Escala/métodos , Mutação/genética , Transtornos Mieloproliferativos/genética , Sondas de DNA/genética , DNA de Neoplasias/genética , Humanos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Sensibilidade e Especificidade
7.
Turk J Pediatr ; 58(1): 113-115, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27922248

RESUMO

We report herein on our observation of recessive congenital methemoglobinemia (type I), an autosomal recessive disorder, in immediate generations (in a mother and her daughter). Molecular analysis revealed a mechanism of inheritance not reported previously, despite the high probability of occurrence in autosomal recessive disorders. This report is also the first publication describing an extremely rare mutation (Arg50Gln) causing this disorder in the Turkish population.


Assuntos
Citocromo-B(5) Redutase/genética , Metemoglobinemia/congênito , Adolescente , Feminino , Humanos , Masculino , Metemoglobinemia/diagnóstico , Metemoglobinemia/genética , Pessoa de Meia-Idade , Mutação , Turquia
8.
Eur J Haematol ; 95(4): 270-9, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25951317

RESUMO

Since the discovery of the JAK2 V617F mutation in the majority of the myeloproliferative neoplasms (MPN) of polycythemia vera, essential thrombocythemia and primary myelofibrosis ten years ago, further MPN-specific mutational events, notably in JAK2 exon 12, MPL exon 10 and CALR exon 9 have been identified. These discoveries have been rapidly incorporated into evolving molecular diagnostic algorithms. Whilst many of these mutations appear to have prognostic implications, establishing MPN diagnosis is of immediate clinical importance with selection, implementation and the continual evaluation of the appropriate laboratory methodology to achieve this diagnosis similarly vital. The advantages and limitations of these approaches in identifying and quantitating the common MPN-associated mutations are considered herein with particular regard to their clinical utility. The evolution of molecular diagnostic applications and platforms has occurred in parallel with the discovery of MPN-associated mutations, and it therefore appears likely that emerging technologies such as next-generation sequencing and digital PCR will in the future play an increasing role in the molecular diagnosis of MPN.


Assuntos
Transtornos Mieloproliferativos/diagnóstico , Transtornos Mieloproliferativos/genética , Calreticulina/genética , Éxons , Humanos , Janus Quinase 2/genética , Janus Quinase 2/metabolismo , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Diagnóstico Molecular/normas , Mutação , Transtornos Mieloproliferativos/metabolismo , Garantia da Qualidade dos Cuidados de Saúde , Receptores de Trombopoetina/genética
9.
Blood Cells Mol Dis ; 54(1): 123-31, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25128083

RESUMO

DEK is important in regulating cellular processes including proliferation, differentiation and maintenance of stem cell phenotype. The translocation t(6;9) in Acute Myeloid Leukemia (AML), which fuses DEK with NUP214, confers a poor prognosis and a higher risk of relapse. The over-expression of DEK in AML has been reported, but different studies have shown diminished levels in pediatric and promyelocytic leukemias. This study has characterized DEK expression, in silico, using a large multi-center cohort of leukemic and normal control cases. Overall, DEK was under-expressed in AML compared to normal bone marrow (NBM). Studying specific subtypes of AML confirmed either no significant change or a significant reduction in DEK expression compared to NBM. Importantly, the similarity of DEK expression between AML and NBM was confirmed using immunohistochemistry analysis of tissue mircorarrays. In addition, stratification of AML patients based on median DEK expression levels indicated that DEK showed no effect on the overall survival of patients. DEK expression during normal hematopoiesis did reveal a relationship with specific cell types implicating a distinct function during myeloid differentiation. Whilst DEK may play a potential role in hematopoiesis, it remains to be established whether it is important for leukemagenesis, except when involved in the t(6;9) translocation.


Assuntos
Proteínas Cromossômicas não Histona/biossíntese , Proteínas de Ligação a DNA/biossíntese , Bases de Dados Genéticas , Regulação Leucêmica da Expressão Gênica , Hematopoese , Leucemia Mieloide Aguda/metabolismo , Proteínas Oncogênicas/biossíntese , Animais , Proteínas Cromossômicas não Histona/genética , Cromossomos Humanos Par 6/genética , Cromossomos Humanos Par 9/genética , Estudos de Coortes , Proteínas de Ligação a DNA/genética , Intervalo Livre de Doença , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Estudos Multicêntricos como Assunto , Proteínas Oncogênicas/genética , Proteínas de Ligação a Poli-ADP-Ribose , Taxa de Sobrevida , Translocação Genética
10.
Fam Cancer ; 13(4): 659-63, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25103330

RESUMO

The myeloproliferative neoplasms (MPN) are clonal, hematological malignancies that include polycythemia vera, essential thrombocythemia and primary myelofibrosis. While most cases of MPN are sporadic in nature, a familial pattern of inheritance is well recognised. The phenotype and status of the commonly acquired JAK2 V617F, CALR exon 9 and MPL W515L/K mutations in affected individuals from a consecutive series of ten familial MPN (FMPN) kindred are described. Affected individuals display the classical MPN phenotypes together with one kindred identified suggestive of hereditary thrombocytosis. In affected patients the JAK2 V617F mutation is the most commonly acquired followed by CALR exon nine mutations with no MPL W515L/K mutations detected. The JAK2 V617F and CALR exon 9 mutations appear to occur at approximately the same frequency in FMPN as in the sporadic forms of these diseases. The familial nature of MPN may often be overlooked and accordingly more common than previously considered. Characterisation of these FMPN kindred may allow for the investigation of molecular events that contribute to this inheritance.


Assuntos
Calreticulina/genética , Predisposição Genética para Doença/genética , Neoplasias Hematológicas/genética , Janus Quinase 2/genética , Receptores de Trombopoetina/genética , Análise Mutacional de DNA , Feminino , Humanos , Masculino , Mutação , Linhagem , Fenótipo
11.
Hypoxia (Auckl) ; 2: 71-90, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-27774468

RESUMO

The transcription of the erythropoietin (EPO) gene is tightly regulated by the hypoxia response pathway to maintain oxygen homeostasis. Elevations in serum EPO level may be reflected in an augmentation in the red cell mass, thereby causing erythrocytosis. Studies on erythrocytosis have provided insights into the function of the oxygen-sensing pathway and the critical proteins involved in the regulation of EPO transcription. The α subunits of the hypoxia-inducible transcription factor are hydroxylated by three prolyl hydroxylase domain (PHD) enzymes, which belong to the iron and 2-oxoglutarate-dependent oxygenase superfamily. Sequence analysis of the genes encoding the PHDs in patients with erythrocytosis has revealed heterozygous germline mutations only occurring in Egl nine homolog 1 (EGLN1, also known as PHD2), the gene that encodes PHD2. To date, 24 different EGLN1 mutations comprising missense, frameshift, and nonsense mutations have been described. The phenotypes associated with the patients carrying these mutations are fairly homogeneous and typically limited to erythrocytosis with normal to elevated EPO. However, exceptions exist; for example, there is one case with development of concurrent paraganglioma (PHD2-H374R). Analysis of the erythrocytosis-associated PHD2 missense mutations has shown heterogeneous results. Structural studies reveal that mutations can affect different domains of PHD2. Some are close to the hypoxia-inducible transcription factor α/2-oxoglutarate or the iron binding sites for PHD2. In silico studies demonstrate that the mutations do not always affect fully conserved residues. In vitro and in cellulo studies showed varying effects of the mutations, ranging from mild effects to severe loss of function. The exact mechanism of a potential tumor-suppressor role for PHD2 still needs to be elucidated. A knockin mouse model expressing the first reported PHD2-P317R mutation recapitulates the phenotype observed in humans (erythrocytosis with inappropriately normal serum EPO levels) and demonstrates that haploinsufficiency and partial deregulation of PHD2 is sufficient to cause erythrocytosis.

13.
Int J Evid Based Healthc ; 12(1): 31-8, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24685898

RESUMO

This paper describes the challenges encountered by an academic team when working with clinical teams to translated knowledge for the purposes of quality improvement in multiple sites. The sites were four differing health care settings in a Northeastern US state: two acute care hospital sites (one rural, one urban), one visiting nurse service and one psychiatric specialty hospital were purposively chosen for the action research study. In conducting this study at these diverse sites the importance of developing relationships and trust, understanding the context and dealing with real world complexities were evident. We conclude with observations and recommendations on important elements for effective knowledge translation work.


Assuntos
Centros Médicos Acadêmicos , Comportamento Cooperativo , Prática Clínica Baseada em Evidências , Relações Interprofissionais , Guias de Prática Clínica como Assunto , Pesquisa Translacional Biomédica/organização & administração , Pesquisa sobre Serviços de Saúde , New England , Garantia da Qualidade dos Cuidados de Saúde , Melhoria de Qualidade/organização & administração
14.
Br J Haematol ; 165(4): 519-28, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24533580

RESUMO

Primary familial and congenital polycythaemia (PFCP) is a disease characterized by increased red blood cell mass, and can be associated with mutations in the intracellular region of the erythropoietin (EPO) receptor (EPOR). Here we explore the mechanisms by which EPOR mutations induce PFCP, using an experimental system based on chimeric receptors between epidermal growth factor receptor (EGFR) and EPOR. The design of the chimeras enabled EPOR signalling to be triggered by EGF binding. Using this system we analysed three novel EPOR mutations discovered in PFCP patients: a deletion mutation (Del1377-1411), a nonsense mutation (C1370A) and a missense mutation (G1445A). Three different chimeras, bearing these mutations in the cytosolic, EPOR region were generated; Hence, the differences in the chimera-related effects are specifically attributed to the mutations. The results show that the different mutations affect various aspects related to the signalling and metabolism of the chimeric receptors. These include slower degradation rate, higher levels of glycan-mature chimeric receptors, increased sensitivity to low levels of EGF (replacing EPO in this system) and extended signalling cascades. This study provides a novel experimental system to study polycythaemia-inducing mutations in the EPOR, and sheds new light on underlying mechanisms of EPOR over-activation in PFCP patients.


Assuntos
Policitemia/congênito , Receptores da Eritropoetina/genética , Linhagem Celular , Membrana Celular/metabolismo , Códon sem Sentido , Análise Mutacional de DNA , Receptores ErbB/genética , Glicosilação , Humanos , Técnicas In Vitro , Janus Quinase 2/metabolismo , Sistema de Sinalização das MAP Quinases , Mutação de Sentido Incorreto , Policitemia/genética , Polissacarídeos/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Processamento de Proteína Pós-Traducional , Estrutura Terciária de Proteína , Receptores da Eritropoetina/química , Receptores da Eritropoetina/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Fator de Transcrição STAT5/fisiologia , Deleção de Sequência , Transdução de Sinais/genética , Relação Estrutura-Atividade , Transfecção
15.
Hum Mutat ; 35(1): 15-26, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24115288

RESUMO

Congenital erythrocytosis (CE), or congenital polycythemia, represents a rare and heterogeneous clinical entity. It is caused by deregulated red blood cell production where erythrocyte overproduction results in elevated hemoglobin and hematocrit levels. Primary congenital familial erythrocytosis is associated with low erythropoietin (Epo) levels and results from mutations in the Epo receptor gene (EPOR). Secondary CE arises from conditions causing tissue hypoxia and results in increased Epo production. These include hemoglobin variants with increased affinity for oxygen (HBB, HBA mutations), decreased production of 2,3-bisphosphoglycerate due to BPGM mutations, or mutations in the genes involved in the hypoxia sensing pathway (VHL, EPAS1, and EGLN1). Depending on the affected gene, CE can be inherited either in an autosomal dominant or recessive mode, with sporadic cases arising de novo. Despite recent important discoveries in the molecular pathogenesis of CE, the molecular causes remain to be identified in about 70% of the patients. With the objective of collecting all the published and unpublished cases of CE the COST action MPN&MPNr-Euronet developed a comprehensive Internet-based database focusing on the registration of clinical history, hematological, biochemical, and molecular data (http://www.erythrocytosis.org/). In addition, unreported mutations are also curated in the corresponding Leiden Open Variation Database.


Assuntos
Bases de Dados Genéticas , Predisposição Genética para Doença , Mutação , Policitemia/congênito , Receptores da Eritropoetina/genética , Hipóxia Celular/genética , Eritropoetina/metabolismo , Humanos , Internet , Policitemia/genética , Policitemia/metabolismo , Transdução de Sinais/genética
17.
Blood ; 123(3): 366-76, 2014 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-24196071

RESUMO

Neutrophil lifespan and function are regulated by hypoxia via components of the hypoxia inducible factor (HIF)/von Hippel Lindau/hydroxylase pathway, including specific roles for HIF-1α and prolyl hydroxylase-3. HIF-2α has both distinct and overlapping biological roles with HIF-1α and has not previously been studied in the context of neutrophil biology. We investigated the role of HIF-2α in regulating key neutrophil functions. Human and murine peripheral blood neutrophils expressed HIF-2α, with expression up-regulated by acute and chronic inflammatory stimuli and in disease-associated inflammatory neutrophil. HIF2A gain-of-function mutations resulted in a reduction in neutrophil apoptosis both ex vivo, through the study of patient cells, and in vivo in a zebrafish tail injury model. In contrast, HIF-2α-deficient murine inflammatory neutrophils displayed increased sensitivity to nitrosative stress induced apoptosis ex vivo and increased neutrophil apoptosis in vivo, resulting in a reduction in neutrophilic inflammation and reduced tissue injury. Expression of HIF-2α was temporally dissociated from HIF-1α in vivo and predominated in the resolution phase of inflammation. These data support a critical and selective role for HIF-2α in persistence of neutrophilic inflammation and provide a platform to dissect the therapeutic utility of targeting HIF-2α in chronic inflammatory diseases.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Regulação da Expressão Gênica , Inflamação , Neutrófilos/metabolismo , Animais , Apoptose , Hipóxia Celular , Proteínas de Fluorescência Verde/metabolismo , Humanos , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos C57BL , Muramidase , Neutrófilos/citologia , Fagocitose , Fenótipo , RNA/metabolismo , Explosão Respiratória , Peixe-Zebra
18.
J Biol Chem ; 288(47): 33571-33584, 2013 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-24121508

RESUMO

The central pathway for controlling red cell mass is the PHD (prolyl hydroxylase domain protein):hypoxia-inducible factor (HIF) pathway. HIF, which is negatively regulated by PHD, activates numerous genes, including ones involved in erythropoiesis, such as the ERYTHROPOIETIN (EPO) gene. Recent studies have implicated PHD2 as the key PHD isoform regulating red cell mass. Studies of humans have identified erythrocytosis-associated, heterozygous point mutations in the PHD2 gene. A key question concerns the mechanism by which human mutations lead to phenotypes. In the present report, we generated and characterized a mouse line in which a P294R knock-in mutation has been introduced into the mouse Phd2 locus to model the first reported human PHD2 mutation (P317R). Phd2(P294R/+) mice display a degree of erythrocytosis equivalent to that seen in Phd2(+/-) mice. The Phd2(P294R/+)-associated erythrocytosis is reversed in a Hif2a(+/-), but not a Hif1a(+/-) background. Additional studies using various conditional knock-outs of Phd2 reveal that erythrocytosis can be induced by homozygous and heterozygous knock-out of Phd2 in renal cortical interstitial cells using a Pax3-Cre transgene or by homozygous knock-out of Phd2 in hematopoietic progenitors driven by a Vav1-Cre transgene. These studies formally prove that a missense mutation in PHD2 is the cause of the erythrocytosis, show that this occurs through haploinsufficiency, and point to multifactorial control of red cell mass by PHD2.


Assuntos
Haploinsuficiência , Prolina Dioxigenases do Fator Induzível por Hipóxia/metabolismo , Mutação de Sentido Incorreto , Policitemia/metabolismo , Substituição de Aminoácidos , Animais , Modelos Animais de Doenças , Técnicas de Introdução de Genes , Humanos , Prolina Dioxigenases do Fator Induzível por Hipóxia/genética , Camundongos , Camundongos Transgênicos , Policitemia/genética , Policitemia/patologia
19.
Pediatr Blood Cancer ; 60(11): 1734-8, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23776154

RESUMO

During recent years, the increasing knowledge of genetic and physiological changes in polycythemia vera (PV) and of different types of congenital erythrocytosis has led to fundamental changes in recommendations for the diagnostic approach to patients with erythrocytosis. Although widely accepted for adult patients this approach may not be appropriate with regard to children and adolescents affected by erythrocytosis. The "congenital erythrocytosis" working group established within the framework of the MPN&MPNr-EuroNet (COST action BM0902) addressed this question in a consensus finding process and developed a specific algorithm for the diagnosis of erythrocytosis in childhood and adolescence which is presented here.


Assuntos
Algoritmos , Policitemia/classificação , Policitemia/diagnóstico , Adolescente , Adulto , Criança , Humanos
20.
J Biol Chem ; 288(24): 17134-44, 2013 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-23640890

RESUMO

The central pathway for oxygen-dependent control of red cell mass is the prolyl hydroxylase domain protein (PHD):hypoxia inducible factor (HIF) pathway. PHD site specifically prolyl hydroxylates the transcription factor HIF-α, thereby targeting the latter for degradation. Under hypoxia, this modification is attenuated, allowing stabilized HIF-α to activate target genes, including that for erythropoietin (EPO). Studies employing genetically modified mice point to Hif-2α, one of two main Hif-α isoforms, as being the critical regulator of Epo in the adult mouse. More recently, erythrocytosis patients with heterozygous point mutations in the HIF2A gene have been identified; whether these mutations were polymorphisms unrelated to the phenotype could not be ruled out. In the present report, we characterize a mouse line bearing a G536W missense mutation in the Hif2a gene that corresponds to the first such human mutation identified (G537W). We obtained mice bearing both heterozygous and homozygous mutations at this locus. We find that these mice display, in a mutation dose-dependent manner, erythrocytosis and pulmonary hypertension with a high degree of penetrance. These findings firmly establish missense mutations in HIF-2α as a cause of erythrocytosis, highlight the importance of this HIF-α isoform in erythropoiesis, and point to physiologic consequences of HIF-2α dysregulation.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Hipertensão Pulmonar/genética , Mutação de Sentido Incorreto , Policitemia/genética , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Gasometria , Células Cultivadas , Modelos Animais de Doenças , Endotelina-1/genética , Endotelina-1/metabolismo , Eritropoese , Eritropoetina/sangue , Eritropoetina/genética , Expressão Gênica , Técnicas de Introdução de Genes , Estudos de Associação Genética , Humanos , Hipertensão Pulmonar/sangue , Hipertensão Pulmonar/fisiopatologia , Hipertrofia Ventricular Direita/sangue , Hipertrofia Ventricular Direita/genética , Hipertrofia Ventricular Direita/fisiopatologia , Rim/metabolismo , Pulmão/metabolismo , Pulmão/patologia , Pulmão/fisiopatologia , Camundongos , Camundongos Endogâmicos C57BL , Mutagênese , Policitemia/sangue , Policitemia/fisiopatologia , Proteínas Proto-Oncogênicas c-sis/genética , Proteínas Proto-Oncogênicas c-sis/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Taxa Respiratória , Regulação para Cima , Fator A de Crescimento do Endotélio Vascular/sangue
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...