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2.
Haematologica ; 102(6): 1054-1065, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28280079

RESUMO

Aldehyde dehydrogenase 1A1 (ALDH1A1) activity is high in hematopoietic stem cells and functions in part to protect stem cells from reactive aldehydes and other toxic compounds. In contrast, we found that approximately 25% of all acute myeloid leukemias expressed low or undetectable levels of ALDH1A1 and that this ALDH1A1- subset of leukemias correlates with good prognosis cytogenetics. ALDH1A1- cell lines as well as primary leukemia cells were found to be sensitive to treatment with compounds that directly and indirectly generate toxic ALDH substrates including 4-hydroxynonenal and the clinically relevant compounds arsenic trioxide and 4-hydroperoxycyclophosphamide. In contrast, normal hematopoietic stem cells were relatively resistant to these compounds. Using a murine xenotransplant model to emulate a clinical treatment strategy, established ALDH1A1- leukemias were also sensitive to in vivo treatment with cyclophosphamide combined with arsenic trioxide. These results demonstrate that targeting ALDH1A1- leukemic cells with toxic ALDH1A1 substrates such as arsenic and cyclophosphamide may be a novel targeted therapeutic strategy for this subset of acute myeloid leukemias.


Assuntos
Aldeído Desidrogenase/deficiência , Quimioterapia Combinada/métodos , Leucemia Mieloide Aguda/tratamento farmacológico , Família Aldeído Desidrogenase 1 , Animais , Trióxido de Arsênio , Arsenicais/uso terapêutico , Células Cultivadas , Ciclofosfamida/uso terapêutico , Xenoenxertos , Humanos , Leucemia Mieloide Aguda/enzimologia , Camundongos , Terapia de Alvo Molecular , Óxidos/uso terapêutico , Retinal Desidrogenase
3.
Mol Ther ; 25(3): 593-605, 2017 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-28190779

RESUMO

Recently, an engineered Homeobox-nucleoporin fusion gene, NUP98-HOXA10HD or NA10HD, was reported to expand and maintain murine hematopoietic stem cells (HSCs). We postulated that NA10HD would increase the number of human γ-globin-expressing cells to therapeutic levels. We developed a double gene lentiviral vector encoding both human γ-globin and NA10HD, which was used to transduce human peripheral blood CD34+ cells and increased engraftment 2- to 2.5-fold at 15 weeks post-transplantation in immunodeficient mice. In ß-thalassemic mice transplanted with ß-thalassemic HSCs transduced with the γ-globin/NA10HD vector, the number of fetal hemoglobin (HbF)-expressing cells was significantly increased after 3 months, leading to resolution of the anemia. Furthermore, the increases in HbF were maintained at 6 months and persisted after secondary transplantation. In addition, NA10HD enrichment of transduced HSCs led to HbF increases without affecting homeostasis of the white blood cell lineages. Our results suggest that NA10HD increases the number of γ-globin-transduced HSCs that engraft, leading to an elevated number of fetal hemoglobin-containing red cells. These effects of NA10HD provide an improved platform for testing of the therapeutic efficacy of novel globin vectors and provide further impetus to develop safe and effective methods for selective expansion of genetically modified cells.


Assuntos
Vetores Genéticos/genética , Células-Tronco Hematopoéticas/metabolismo , Proteínas de Homeodomínio/genética , Lentivirus/genética , Complexo de Proteínas Formadoras de Poros Nucleares/genética , Proteínas de Fusão Oncogênica/genética , Talassemia beta/genética , gama-Globinas/genética , Animais , Modelos Animais de Doenças , Eritrócitos/citologia , Eritrócitos/metabolismo , Hemoglobina Fetal/metabolismo , Ordem dos Genes , Técnicas de Transferência de Genes , Loci Gênicos , Sobrevivência de Enxerto , Transplante de Células-Tronco Hematopoéticas , Proteínas Homeobox A10 , Humanos , Camundongos , Transdução Genética , Transplante Heterólogo , Talassemia beta/metabolismo , Talassemia beta/terapia
4.
Blood ; 129(3): 319-323, 2017 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-27827825

RESUMO

There is high interest in understanding the mechanisms that drive self-renewal of stem cells. HOXB4 is one of the few transcription factors that can amplify long-term repopulating hematopoietic stem cells in a controlled way. Here we show in mice that this characteristic of HOXB4 depends on a proline-rich sequence near the N terminus, which is unique among HOX genes and highly conserved in higher mammals. Deletion of this domain substantially enhanced the oncogenicity of HOXB4, inducing acute leukemia in mice. Conversely, insertion of the domain into Hoxa9 impaired leukemogenicity of this homeobox gene. These results indicate that proline-rich stretches attenuate the potential of stem cell active homeobox genes to acquire oncogenic properties.


Assuntos
Autorrenovação Celular , Células-Tronco Hematopoéticas/fisiologia , Proteínas de Homeodomínio/fisiologia , Leucemia/etiologia , Fatores de Transcrição/fisiologia , Doença Aguda , Animais , Carcinógenos , Proteínas de Homeodomínio/genética , Camundongos , Prolina , Análise de Sequência de Proteína , Fatores de Transcrição/genética
5.
Blood ; 127(21): 2575-86, 2016 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-26941401

RESUMO

Herein we demonstrate that oncolytic herpes simplex virus-1 (HSV-1) potently activates human peripheral blood mononuclear cells (PBMCs) to lyse leukemic cell lines and primary acute myeloid leukemia samples, but not healthy allogeneic lymphocytes. Intriguingly, we found that UV light-inactivated HSV-1 (UV-HSV-1) is equally effective in promoting PBMC cytolysis of leukemic cells and is 1000- to 10 000-fold more potent at stimulating innate antileukemic responses than UV-inactivated cytomegalovirus, vesicular stomatitis virus, reovirus, or adenovirus. Mechanistically, UV-HSV-1 stimulates PBMC cytolysis of leukemic cells, partly via Toll-like receptor-2/protein kinase C/nuclear factor-κB signaling, and potently stimulates expression of CD69, degranulation, migration, and cytokine production in natural killer (NK) cells, suggesting that surface components of UV-HSV-1 directly activate NK cells. Importantly, UV-HSV-1 synergizes with interleukin-15 (IL-15) and IL-2 in inducing activation and cytolytic activity of NK cells. Additionally, UV-HSV-1 stimulates glycolysis and fatty acid oxidation-dependent oxygen consumption in NK cells, but only glycolysis is required for their enhanced antileukemic activity. Last, we demonstrate that T cell-depleted human PBMCs exposed to UV-HSV-1 provide a survival benefit in a murine xenograft model of human acute myeloid leukemia (AML). Taken together, our results support the preclinical development of UV-HSV-1 as an adjuvant, alone or in combination with IL-15, for allogeneic donor mononuclear cell infusions to treat AML.


Assuntos
Herpesvirus Humano 1/imunologia , Imunidade Celular , Células Matadoras Naturais/imunologia , Leucemia/imunologia , Raios Ultravioleta , Inativação de Vírus/efeitos da radiação , Degranulação Celular/imunologia , Movimento Celular/imunologia , Feminino , Humanos , Interleucina-15/imunologia , Interleucina-2/imunologia , Células Jurkat , Masculino , NF-kappa B/imunologia , Proteína Quinase C/imunologia , Transdução de Sinais/imunologia , Receptor 2 Toll-Like/imunologia
6.
Blood ; 127(16): 2018-27, 2016 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-26834243

RESUMO

Acute myeloid leukemia (AML) is a genetically heterogeneous hematologic malignancy, which is initiated and driven by a rare fraction of leukemia stem cells (LSCs). Despite the difficulties of identifying a common LSC phenotype, there is increasing evidence that high expression of stem cell gene signatures is associated with poor clinical outcome. Identification of functionally distinct subpopulations in this disease is therefore crucial to dissecting the molecular machinery underlying LSC self-renewal. Here, we combined next-generation sequencing technology with in vivo assessment of LSC frequencies and identified the adhesion G protein-coupled receptor 56 (GPR56) as a novel and stable marker for human LSCs for the majority of AML samples. High GPR56 expression was significantly associated with high-risk genetic subgroups and poor outcome. Analysis of GPR56 in combination with CD34 expression revealed engraftment potential of GPR56(+)cells in both the CD34(-)and CD34(+)fractions, thus defining a novel LSC compartment independent of the CD34(+)CD38(-)LSC phenotype.


Assuntos
Biomarcadores Tumorais/metabolismo , Proliferação de Células , Leucemia Mieloide Aguda/patologia , Células-Tronco Neoplásicas/patologia , Receptores Acoplados a Proteínas G/metabolismo , Adulto , Animais , Separação Celular , Células Cultivadas , Células HEK293 , Humanos , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/mortalidade , Camundongos , Camundongos Endogâmicos NOD , Camundongos Transgênicos , Células-Tronco Neoplásicas/fisiologia , Receptores Acoplados a Proteínas G/fisiologia , Análise de Sobrevida
7.
PLoS One ; 11(1): e0147059, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26761813

RESUMO

Techniques to expand human hematopoietic stem cells ex-vivo could be beneficial to the fields of clinical hematopoietic stem cell transplantation and gene therapy targeted at hematopoietic stem cells. NUP98-HOXA10HD is a relatively newly discovered fusion gene that in mouse transplant experiments has been shown to increase numbers of hematopoietic stem cells. We evaluated whether this fusion gene could be used to expand engrafting human primitive CD34+ cells in an immunodeficient mouse model. Gene transfer was achieved using a lentiviral based vector. The engraftment of mobilized peripheral blood human CD34+ cells grown in culture for one week after gene transfer was evaluated 3-4 months after transplant and found to be 2-3 fold higher in the NUP98-HOXA10HD groups as compared to controls. These data suggest an expansive effect at least at the short term human repopulating cell level. Further evaluation in long term repopulating models and investment in a NUP98-HOXA10HD protein seems worthy of consideration. Additionally, the results here provide strong impetus to utilize NUP98-HOXA10HD as a tool to search for underlying genes and pathways involved in hematopoietic stem cell expansion that can be enhanced and have an even more potent expansive effect.


Assuntos
Expressão Gênica , Sobrevivência de Enxerto , Transplante de Células-Tronco Hematopoéticas , Células-Tronco Hematopoéticas/metabolismo , Proteínas de Homeodomínio/genética , Complexo de Proteínas Formadoras de Poros Nucleares/genética , Proteínas Recombinantes de Fusão/genética , Animais , Antígenos de Superfície/metabolismo , Ordem dos Genes , Vetores Genéticos/genética , Proteínas Homeobox A10 , Proteínas de Homeodomínio/química , Humanos , Imunofenotipagem , Subunidade gama Comum de Receptores de Interleucina/deficiência , Subunidade gama Comum de Receptores de Interleucina/genética , Lentivirus/genética , Camundongos , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Modelos Animais , Transdução Genética
8.
Ann N Y Acad Sci ; 1310: 58-68, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24641679

RESUMO

Acute myeloid leukemia (AML) affects approximately 15,000 persons per year in the United States and is the sixth leading cause of cancer-related deaths. The treatment of AML has advanced little in the past thirty years, in part because of the biologic heterogeneity of the disease and the difficulty in targeting AML cells while sparing normal hematopoietic cells. Advances in preventing and treating AML are likely to occur once the cellular and molecular differences between leukemia and normal hematopoietic cells are better understood. Aldehyde dehydrogenase (ALDH) activity is highly expressed in hematopoietic stem cells (HSCs), while, in contrast, a subset of AMLs are lacking this activity. This difference may be relevant to the development of AML and may also provide a better avenue for treating this disease. In this review, we summarize what is known about the ALDHs in normal HSCs and AML and propose strategies for capitalizing on these differences in the treatment of acute leukemia, and possibly other cancers as well.


Assuntos
Aldeído Desidrogenase/fisiologia , Células-Tronco Hematopoéticas/enzimologia , Leucemia Mieloide Aguda/enzimologia , Animais , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Heterogeneidade Genética , Hematopoese/genética , Humanos , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/terapia , Prognóstico
9.
Blood ; 122(9): 1545-55, 2013 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-23777767

RESUMO

Histone methylation is a dynamic and reversible process proposed to directly impact on stem cell fate. The Jumonji (JmjC) domain-containing family of demethylases comprises 27 members that target mono-, di-, and trimethylated lysine residues of histone (or nonhistone) proteins. To evaluate their role in regulation of hematopoietic stem cell (HSC) behavior, we performed an in vivo RNAi-based functional screen and demonstrated that Jarid1b and Jhdm1f play opposing roles in regulation of HSC activity. Decrease in Jarid1b levels correlated with an in vitro expansion of HSCs with preserved long-term in vivo lymphomyeloid differentiation potential. Through RNA sequencing analysis, Jarid1b knockdown was associated with increased expression levels of several HSC regulators (Hoxa7, Hoxa9, Hoxa10, Hes1, Gata2) and reduced levels of differentiation-associated genes. shRNA against Jhdmlf, in contrast, impaired hematopoietic reconstitution of bone marrow cells. Together, our studies identified Jarid1b as a negative regulator of HSC activity and Jhdmlf as a positive regulator of HSC activity.


Assuntos
Proteínas de Ligação a DNA/fisiologia , Hematopoese/genética , Células-Tronco Hematopoéticas/fisiologia , Ensaios de Triagem em Larga Escala/métodos , Histona Desmetilases com o Domínio Jumonji/fisiologia , Interferência de RNA/fisiologia , Animais , Células Cultivadas , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Hematopoese/efeitos dos fármacos , Células-Tronco Hematopoéticas/metabolismo , Histona Desmetilases/genética , Histona Desmetilases/fisiologia , Histona Desmetilases com o Domínio Jumonji/genética , Camundongos , Camundongos Congênicos , Camundongos Endogâmicos C57BL , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/farmacologia , Fatores de Transcrição/genética , Fatores de Transcrição/fisiologia , Estudos de Validação como Assunto
10.
Spine (Phila Pa 1976) ; 38(4): E230-6, 2013 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-23197013

RESUMO

STUDY DESIGN: Prospective, clinical, noninvasive imaging study. OBJECTIVE: To quantify normal lumbar artery hemodynamics and develop a reference range and lumbar artery hemodynamics in patients with low back pain. SUMMARY OF BACKGROUND DATA: Blood supply to the lumbar spinal tissues, intraosseous capillary circulation, and avascular intervertebral discs derives directly from the lumbar arteries. Pathology may affect this blood supply, impact nutrient delivery and contribute to low back pain and disc degeneration. However knowledge of hemodynamic characteristics of lumbar arteries is lacking. This could improve understanding into pathological tissue function and its relation to lumbar spine circulation in back disorders. METHODS: Sixty-four patients with low back pain and 30 normal controls underwent lumbar spine imaging investigations with color Doppler ultrasonography. Doppler data on blood flow was obtained from arteries at S1 through to L1 bilaterally and angle-corrected peak systolic blood flow velocity (PSV) measured in all vessels. Aortic PSV was used to derive the normalized lumbar artery: Aortic PSV ratio (PSVR) for all subjects' levels L1 to S1 bilaterally. RESULTS: In both the control and low back pain (LBP) groups blood flow PSV in the lumbar arteries increased incrementally from levels L1 to L4, declined to its lowest values at L5 and rose again at S1. Normalized lumbar artery blood flow PSVR in the LBP group is consistently higher at all levels (L1-S1) than in controls (P < 0.001). At level L5, lumbar artery blood flow PSVR was 46% higher in the LBP group than in controls. CONCLUSION: Color Doppler ultrasonography can reliably be used as a clinical tool to visualize and quantify blood flow in lumbar arteries of patients with low back disorders. Findings of increased blood flow PSVR in patients are consistent with the well-documented Doppler changes that occur during inflammatory hyperemia. LEVEL OF EVIDENCE: 3.


Assuntos
Dor Lombar/diagnóstico por imagem , Vértebras Lombares/irrigação sanguínea , Ultrassonografia Doppler em Cores , Adulto , Idoso , Idoso de 80 Anos ou mais , Artérias/diagnóstico por imagem , Artérias/fisiopatologia , Velocidade do Fluxo Sanguíneo , Estudos de Casos e Controles , Feminino , Humanos , Dor Lombar/fisiopatologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Fluxo Sanguíneo Regional , Análise de Regressão , Adulto Jovem
11.
Cancer Cell ; 20(5): 674-88, 2011 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-22094260

RESUMO

To identify FDA-approved agents targeting leukemic cells, we performed a chemical screen on two human leukemic cell lines and identified the antimicrobial tigecycline. A genome-wide screen in yeast identified mitochondrial translation inhibition as the mechanism of tigecycline-mediated lethality. Tigecycline selectively killed leukemia stem and progenitor cells compared to their normal counterparts and also showed antileukemic activity in mouse models of human leukemia. ShRNA-mediated knockdown of EF-Tu mitochondrial translation factor in leukemic cells reproduced the antileukemia activity of tigecycline. These effects were derivative of mitochondrial biogenesis that, together with an increased basal oxygen consumption, proved to be enhanced in AML versus normal hematopoietic cells and were also important for their difference in tigecycline sensitivity.


Assuntos
Antineoplásicos/farmacologia , Genes Mitocondriais , Leucemia/tratamento farmacológico , Minociclina/análogos & derivados , Mitocôndrias/efeitos dos fármacos , Células-Tronco Neoplásicas/efeitos dos fármacos , Biossíntese de Proteínas/efeitos dos fármacos , Animais , Linhagem Celular Tumoral , Humanos , Camundongos , Minociclina/farmacologia , Proteínas Mitocondriais/genética , Fator Tu de Elongação de Peptídeos/genética , RNA Interferente Pequeno , Saccharomyces cerevisiae/efeitos dos fármacos , Tigeciclina
12.
Stem Cells ; 29(4): 736-41, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21328509

RESUMO

Hox genes encode highly conserved transcription factors that have been implicated in hematopoietic development and self-renewal of hematopoietic stem cells (HSCs) and hematopoietic development. The potency of NUP98-HOXA10hd (NA10) on adult murine bone marrow HSC self-renewal prompted us to examine its effect on specification and proliferation of hematopoietic cells derived from human embryonic stem cells (hESCs). Here, we demonstrate that expression of NA10 in hESCs influences the hematopoietic differentiation program. The specific effect of NA10 is dependent on the developmental stage of hematopoietic emergence from hESCs. Overexpression of NA10 in either undifferentiated hESCs or early hemogenic precursors augmented the frequency of CD45(-) GlycophorinA(+) cells and erythroid progenitors (blast-forming unit-erythrocyte). In contrast, targeted NA10 expression in primitive CD34+ cells committed to the hematopoietic lineage had no effect on erythropoietic capacity but instead increased hematopoietic progenitor proliferation. Our study reveals a novel neomorphic effect of NA10 in early human erythroid development from pluripotent stem cells.


Assuntos
Diferenciação Celular , Células-Tronco Embrionárias/metabolismo , Células Eritroides/metabolismo , Eritropoese , Proteínas de Homeodomínio/metabolismo , Complexo de Proteínas Formadoras de Poros Nucleares/metabolismo , Antígenos CD34 , Proliferação de Células , Células Cultivadas , Células-Tronco Embrionárias/citologia , Células Eritroides/citologia , Citometria de Fluxo , Expressão Gênica , Glicoforinas/biossíntese , Proteínas Homeobox A10 , Proteínas de Homeodomínio/genética , Humanos , Antígenos Comuns de Leucócito/biossíntese , Complexo de Proteínas Formadoras de Poros Nucleares/genética
13.
Clin Cancer Res ; 15(7): 2238-47, 2009 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-19276253

RESUMO

PURPOSE: CBL is a negative regulator of activated receptor tyrosine kinases (RTK). In this study, we determined the frequency of CBL mutations in acute leukemias and evaluated the oncogenic potential of mutant CBL. EXPERIMENTAL DESIGN: The cDNA of 300 acute myeloid leukemia (AML)/myelodysplastic syndrome (MDS) and acute lymphoblastic leukemia (ALL) patients and 82 human leukemic cell lines was screened for aberrations in the linker and RING finger domain of CBL. The oncogenic potential of identified mutants was evaluated in hematopoietic cells. RESULTS: We identified 3 of 279 AML/MDS patients expressing CBL exon 8/9 deletion mutants. Three of four cases at diagnosis expressed deleted transcripts missing exon 8 or exon 8/9. In remission samples a weak or no expression of mutant CBL was detected. No aberrations were found in normal hematopoietic tissues. One of 116 sequenced AML/MDS cases carried a R420G missense mutation. All AML/MDS patients with identified CBL mutants belonged to the core binding factor and 11q deletion AML subtypes. Functionally, CBL negatively regulated FMS-like tyrosine kinase 3 (FLT3) activity and interacted with human FLT3 via the autophosphorylation sites Y589 and Y599 and colocalized in vivo. Expression of CBLDeltaexon8 and CBLDeltaexon8+9 in FLT3-WT-Ba/F3 cells induced growth factor-independent proliferation associated with autophosphorylation of FLT3 and activated the downstream targets signal transducer and activator of transcription 5 (STAT5) and protein kinase B (AKT). FLT3 ligand-dependent hyperproliferation of CBL mutant cells could be abrogated by treatment with the FLT3 PTK inhibitor PKC412 (midostaurin). CONCLUSION: CBL exon8/9 mutants occur in genetically defined AML/MDS subtypes and transform hematopoietic cells by constitutively activating the FLT3 pathway. This phenotype resembles the one of mutated RTKs and suggests that CBL mutant AML patients might benefit from treatment with FLT3 PTK inhibitors.


Assuntos
Leucemia Mieloide Aguda/genética , Mutação , Síndromes Mielodisplásicas/genética , Proteínas Proto-Oncogênicas c-cbl/genética , Tirosina Quinase 3 Semelhante a fms/metabolismo , Linhagem Celular Tumoral , Transformação Celular Neoplásica , Deleção Cromossômica , Cromossomos Humanos Par 11 , Fatores de Ligação ao Core/genética , Éxons , Humanos , Leucemia Mieloide Aguda/classificação , Leucemia Mieloide Aguda/metabolismo , Síndromes Mielodisplásicas/classificação , Síndromes Mielodisplásicas/metabolismo , Proteínas Proto-Oncogênicas c-cbl/metabolismo , Deleção de Sequência , Transdução de Sinais
14.
Curr Protoc Stem Cell Biol ; Chapter 2: Unit 2A.7, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18770636

RESUMO

Development of strategies to extensively expand hematopoietic stem cells (HSCs) in vitro will be a major factor in enhancing the success of a range of transplant-based therapies for malignant and genetic disorders. In addition to potential clinical applications, the ability to increase the number of HSCs in culture will facilitate investigations into the mechanisms underlying self-renewal. In this unit, we describe a robust strategy for consistently achieving over 1000-fold net expansion of HSCs in short-term in vitro culture by using novel engineered fusions of the N-terminal domain of nucleoporin 98 (NUP98) and the homeodomain of the hox transcription factor, HOXA10 (so called NUP98-HOXA10hd fusion). We also provide a detailed protocol for monitoring the magnitude of HSC expansion in culture by limiting dilution assay of competitive lympho-myeloid repopulating units (CRU Assay). These procedures provide new possibilities for achieving significant numbers of HSCs in culture, as well as for studying HSCs biochemically and genetically.


Assuntos
Técnicas de Cultura de Células/métodos , Células-Tronco Hematopoéticas/citologia , Animais , Proliferação de Células , Células Cultivadas , Camundongos , Camundongos Endogâmicos C57BL , Complexo de Proteínas Formadoras de Poros Nucleares/metabolismo , Fatores de Tempo , Transdução Genética
15.
Ultrasound Med Biol ; 32(2): 171-82, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16464662

RESUMO

Lumbar arteries are important because they are the main source of blood supply to the lumbar spine structures. However, these vessels and their flow characteristics have received little attention and their role in conditions such as low back pain remains unclear. The present study 1. describes the application of duplex ultrasonography in the assessment of lumbar artery blood flow and 2. evaluates the interobserver and intraobserver reproducibility of lumbar artery Doppler velocimetry. A total of 13 healthy volunteers were evaluated by two different examiners successively on the same day and measurements repeated by the same examiners 1 week later. Peak systolic velocities of lumbar arteries were recorded at an optimal angle below 60 degrees . Overall mean peak systolic velocity (+/-SD) for lumbar arteries was 0.158 +/- 0.051 m/s, and mean Doppler angle (+/-SD) was 24.6 +/- 14.5 degrees . For interobserver variability, the coefficient of variation was 23.4% and SD of differences 0.037 m/s. Reliable results of lumbar artery Doppler velocimetry demonstrate its applicability in future clinical investigations in patients with low back disorders. (E-mail: ).


Assuntos
Região Lombossacral/irrigação sanguínea , Ultrassonografia Doppler em Cores/métodos , Adulto , Artérias/diagnóstico por imagem , Velocidade do Fluxo Sanguíneo/fisiologia , Feminino , Humanos , Região Lombossacral/diagnóstico por imagem , Masculino , Variações Dependentes do Observador , Reprodutibilidade dos Testes
16.
Blood ; 104(8): 2307-14, 2004 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-15226173

RESUMO

HOXB4 overexpression induces unique in vivo and in vitro expansion of hemopoietic stem cells (HSCs) without causing leukemia. Very little is known about the molecular basis underlying HOXB4-induced HSC self-renewal. We now report the in vitro proliferation and in vivo expansion capacity of primary bone marrow (BM) cells engineered to overexpress selected HOXB4 point mutants lacking either the capacity to directly bind DNA (HOXB4(A)), or to cooperate with members of the PBX family (HOXB4(W-->G)) in DNA binding. The DNA binding-incompetent HOXB4 mutant failed to enhance the proliferation activity of transduced BM populations in vitro and HSC expansion in vivo. In contrast, the HOXB4(W-->G) mutant conferred a pronounced in vitro proliferation advantage to the transduced BM populations, and dramatically enhanced their in vivo regenerative potential. We also demonstrate a correlation between HOXB4 protein levels and in vitro proliferative capacity of primary BM cells. Our observations thus suggest that the capacity of HOXB4 to induce HSC expansions is DNA-binding dependent and does not require direct HOX/PBX interaction, and sets the stage for identifying HOXB4-dependent targets involved in HSC expansion.


Assuntos
Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/metabolismo , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Animais , Divisão Celular , Linhagem Celular , DNA/metabolismo , Expressão Gênica , Humanos , Camundongos , Mutação/genética , Ligação Proteica , Triptofano/genética , Triptofano/metabolismo
17.
IEEE Trans Med Imaging ; 23(5): 567-83, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15147010

RESUMO

Three-dimensional (3-D) ultrasound is a relatively new technique, which is well suited to imaging superficial blood vessels, and potentially provides a useful, noninvasive method for generating anatomically realistic 3-D models of the peripheral vasculature. Such models are essential for accurate simulation of blood flow using computational fluid dynamics (CFD), but may also be used to quantify atherosclerotic plaque more comprehensively than routine clinical methods. In this paper, we present a spline-based method for reconstructing the normal and diseased carotid artery bifurcation from images acquired using a freehand 3-D ultrasound system. The vessel wall (intima-media interface) and lumen surfaces are represented by a geometric model defined using smoothing splines. Using this coupled wall-lumen model, we demonstrate how plaque may be analyzed automatically to provide a comprehensive set of quantitative measures of size and shape, including established clinical measures, such as degree of (diameter) stenosis. The geometric accuracy of 3-D ultrasound reconstruction is assessed using pulsatile phantoms of the carotid bifurcation, and we conclude by demonstrating the in vivo application of the algorithms outlined to 3-D ultrasound scans from a series of patient carotid arteries.


Assuntos
Algoritmos , Artéria Carótida Interna/diagnóstico por imagem , Estenose das Carótidas/diagnóstico por imagem , Ecocardiografia Tridimensional/métodos , Interpretação de Imagem Assistida por Computador/métodos , Artéria Carótida Primitiva/diagnóstico por imagem , Artéria Carótida Externa/diagnóstico por imagem , Ecocardiografia Tridimensional/instrumentação , Humanos , Imagens de Fantasmas , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
18.
Blood ; 99(1): 121-9, 2002 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-11756161

RESUMO

Cytogenetic, genetic, and functional studies have demonstrated a direct link between deregulated Hoxa9 expression and acute myeloid leukemia (AML). Hoxa9 overexpression in mouse bone marrow cells invariably leads to AML within 3 to 10 months, suggesting the requirement for additional genetic events prior to AML. To gain further insight into how Hoxa9 affects hematopoietic development at the preleukemic stage, we have engineered its overexpression (1) in hematopoietic stem cells using retrovirus-mediated gene transfer and generated bone marrow transplantation chimeras and (2) in lymphoid cells using transgenic mice. Compared with controls, recipients of Hoxa9-transduced cells had an about 15-fold increase in transplantable lymphomyeloid long-term repopulating cells, indicating the capacity for this oncogene to confer a growth advantage to hematopoietic stem cells. In addition, overexpression of Hoxa9 in more mature cells enhanced granulopoiesis and partially blocked B lymphopoiesis at the pre-B-cell stage but had no detectable effect on T lymphoid development. Interestingly, despite specifically directing high expression of Hoxa9 in T and B lymphoid lineages, none of the Hoxa9 transgenic mice developed lymphoid malignancies for the observation period of more than 18 months.


Assuntos
Células da Medula Óssea/metabolismo , Expressão Gênica , Células-Tronco Hematopoéticas/metabolismo , Proteínas de Homeodomínio/genética , Leucemia Mieloide Aguda/genética , Proteínas de Neoplasias/genética , Animais , Linfócitos B/patologia , Células da Medula Óssea/patologia , Contagem de Células , Divisão Celular , Regulação da Expressão Gênica , Granulócitos , Hematopoese , Células-Tronco Hematopoéticas/patologia , Leucemia Mieloide Aguda/patologia , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Retroviridae/genética , Linfócitos T/patologia , Transfecção , Quimeras de Transplante
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