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1.
Blood ; 132(3): 307-320, 2018 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-29724897

RESUMO

Heat shock protein 90 (HSP90) stabilizes many client proteins, including the BCR-ABL1 oncoprotein. BCR-ABL1 is the hallmark of chronic myeloid leukemia (CML) in which treatment-free remission (TFR) is limited, with clinical and economic consequences. Thus, there is an urgent need for novel therapeutics that synergize with current treatment approaches. Several inhibitors targeting the N-terminal domain of HSP90 are under investigation, but side effects such as induction of the heat shock response (HSR) and toxicity have so far precluded their US Food and Drug Administration approval. We have developed a novel inhibitor (aminoxyrone [AX]) of HSP90 function by targeting HSP90 dimerization via the C-terminal domain. This was achieved by structure-based molecular design, chemical synthesis, and functional preclinical in vitro and in vivo validation using CML cell lines and patient-derived CML cells. AX is a promising potential candidate that induces apoptosis in the leukemic stem cell fraction (CD34+CD38-) as well as the leukemic bulk (CD34+CD38+) of primary CML and in tyrosine kinase inhibitor (TKI)-resistant cells. Furthermore, BCR-ABL1 oncoprotein and related pro-oncogenic cellular responses are downregulated, and targeting the HSP90 C terminus by AX does not induce the HSR in vitro and in vivo. We also probed the potential of AX in other therapy-refractory leukemias. Therefore, AX is the first peptidomimetic C-terminal HSP90 inhibitor with the potential to increase TFR in TKI-sensitive and refractory CML patients and also offers a novel therapeutic option for patients with other types of therapy-refractory leukemia because of its low toxicity profile and lack of HSR.


Assuntos
Antineoplásicos/farmacologia , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Proteínas de Choque Térmico HSP90/química , Resposta ao Choque Térmico/efeitos dos fármacos , Mesilato de Imatinib/farmacologia , Domínios e Motivos de Interação entre Proteínas , Inibidores de Proteínas Quinases/farmacologia , Multimerização Proteica , Animais , Antineoplásicos/química , Sítios de Ligação , Biomarcadores Tumorais , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Proteínas de Fusão bcr-abl/antagonistas & inibidores , Proteínas de Fusão bcr-abl/química , Proteínas de Choque Térmico HSP90/metabolismo , Humanos , Mesilato de Imatinib/química , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Camundongos , Modelos Moleculares , Conformação Molecular , Estrutura Molecular , Ligação Proteica , Inibidores de Proteínas Quinases/química , Multimerização Proteica/efeitos dos fármacos , Análise Espectral , Relação Estrutura-Atividade , Ensaios Antitumorais Modelo de Xenoenxerto
2.
FASEB J ; 33(6): 6933-6947, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30922080

RESUMO

MicroRNAs (miRs) are important posttranscriptional regulators of gene expression. Besides their well-characterized inhibitory effects on mRNA stability and translation, miRs can also activate gene expression. In this study, we identified a novel noncanonical function of miR-574-5p. We found that miR-574-5p acts as an RNA decoy to CUG RNA-binding protein 1 (CUGBP1) and antagonizes its function. MiR-574-5p induces microsomal prostaglandin E synthase-1 (mPGES-1) expression by preventing CUGBP1 binding to its 3'UTR, leading to an enhanced alternative splicing and generation of an mPGES-1 3'UTR isoform, increased mPGES-1 protein expression, PGE2 formation, and tumor growth in vivo. miR-574-5p-induced tumor growth in mice could be completely inhibited with the mPGES-1 inhibitor CIII. Moreover, miR-574-5p is induced by IL-1ß and is strongly overexpressed in human nonsmall cell lung cancer where high mPGES-1 expression correlates with a low survival rate. The discovered function of miR-574-5p as a CUGBP1 decoy opens up new therapeutic opportunities. It might serve as a stratification marker to select lung tumor patients who respond to the pharmacological inhibition of PGE2 formation.-Saul, M. J., Baumann, I., Bruno, A., Emmerich, A. C., Wellstein, J., Ottinger, S. M., Contursi, A., Dovizio, M., Donnini, S., Tacconelli, S., Raouf, J., Idborg, H., Stein, S., Korotkova, M., Savai, R., Terzuoli, E., Sala, G., Seeger, W., Jakobsson, P.-J., Patrignani, P., Suess, B., Steinhilber, D. miR-574-5p as RNA decoy for CUGBP1 stimulates human lung tumor growth by mPGES-1 induction.


Assuntos
Proteínas CELF1/metabolismo , MicroRNAs/metabolismo , Prostaglandina-E Sintases/metabolismo , RNA/metabolismo , Células A549 , Animais , Proteínas CELF1/genética , Proliferação de Células , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HeLa , Humanos , Camundongos , Camundongos Nus , MicroRNAs/genética , Mimetismo Molecular , Neoplasias Experimentais , Prostaglandina-E Sintases/genética , Ligação Proteica , Inibidores da Síntese de Proteínas/farmacologia , Puromicina/farmacologia , RNA/genética , Interferência de RNA , Isoformas de RNA , RNA Mensageiro
3.
Opt Express ; 26(8): 10968-10980, 2018 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-29716025

RESUMO

Laser drop on demand jetting of Cu-base braze droplets was proven a suitable method for joining wires to electrode structures of electronic devices, particularly if the electrical contacts need to withstand high thermal loads. During joining, a braze preform of 600 µm diameter is placed inside a capillary, molten by a laser pulse and subsequently ejected from the capillary by inert gas overpressure similarly to conventional solder ball bumping processes. However, since the liquidus temperature of the used braze material of 990 °C is about 760 °C higher than of standard Sn-based solders used in electronics packaging, the system technology was modified significantly to enable jetting of CuSn alloys. In particular, the beam source emits a five times higher optical output power than standard machines designed for processing Sn-based solders. In addition, a modified capillary made from technical ceramic was machined, to withstand the significantly higher heating- and cooling rates during the process. In order to understand the influence of capillary geometry on droplet detachment, and flight trajectory, two capillary geometries were machined applying a picosecond laser ablation process. Subsequently, stereoscopic high speed videos of droplet detachment and flight phase were analyzed. Using this approach it is possible, to determine droplet flight trajectories, velocities and lateral positional deviations in dependency of relative inert gas overpressure inside the machining head, pulse power and capillary geometry. The findings indicate a significant influence of the capillary geometry and the applied overpressure on the droplet flight trajectory, whereas the role of the laser pulse power seems neglectable.

4.
J Allergy Clin Immunol ; 138(1): 219-228.e9, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26853280

RESUMO

BACKGROUND: Defects in phagocytic nicotinamide adenine dinucleotide phosphate oxidase 2 (NOX2) function cause chronic granulomatous disease (CGD), a primary immunodeficiency characterized by dysfunctional microbicidal activity and chronic inflammation. OBJECTIVE: We sought to study the effect of chronic inflammation on the hematopoietic compartment in patients and mice with X-linked chronic granulomatous disease (X-CGD). METHODS: We used immunostaining and functional analyses to study the hematopoietic compartment in patients with CGD. RESULTS: An analysis of bone marrow cells from patients and mice with X-CGD revealed a dysregulated hematopoiesis characterized by increased numbers of hematopoietic progenitor cells (HPCs) at the expense of repopulating hematopoietic stem cells (HSCs). In patients with X-CGD, there was a clear reduction in the proportion of HSCs in bone marrow and peripheral blood, and they were also more rapidly exhausted after in vitro culture. In mice with X-CGD, increased cycling of HSCs, expansion of HPCs, and impaired long-term engraftment capacity were found to be associated with high concentrations of proinflammatory cytokines, including IL-1ß. Treatment of wild-type mice with IL-1ß induced enhanced cell-cycle entry of HSCs, expansion of HPCs, and defects in long-term engraftment, mimicking the effects observed in mice with X-CGD. Inhibition of cytokine signaling in mice with X-CGD reduced HPC numbers but had only minor effects on the repopulating ability of HSCs. CONCLUSIONS: Persistent chronic inflammation in patients with CGD is associated with hematopoietic proliferative stress, leading to a decrease in the functional activity of HSCs. Our observations have clinical implications for the development of successful autologous cell therapy approaches.


Assuntos
Doença Granulomatosa Crônica/metabolismo , Células-Tronco Hematopoéticas/metabolismo , Adolescente , Adulto , Animais , Biomarcadores , Estudos de Casos e Controles , Contagem de Células , Diferenciação Celular , Criança , Pré-Escolar , Ensaio de Unidades Formadoras de Colônias , Citocinas/metabolismo , Citocinas/farmacologia , Modelos Animais de Doenças , Sobrevivência de Enxerto , Doença Granulomatosa Crônica/etiologia , Transplante de Células-Tronco Hematopoéticas , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/efeitos dos fármacos , Humanos , Imunofenotipagem , Mediadores da Inflamação/metabolismo , Camundongos , Camundongos Transgênicos , Modelos Biológicos , Fenótipo , Transdução de Sinais , Adulto Jovem
5.
Int J Mol Sci ; 18(12)2017 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-29186036

RESUMO

Although a lot of research has been performed, large segmental bone defects caused by trauma, infection, bone tumors or revision surgeries still represent big challenges for trauma surgeons. New and innovative bone substitutes are needed. Three-dimensional (3D) printing is a novel procedure to create 3D porous scaffolds that can be used for bone tissue engineering. In the present study, solid discs as well as porous cage-like 3D prints made of polylactide (PLA) are coated or filled with collagen, respectively, and tested for biocompatibility and endotoxin contamination. Microscopic analyses as well as proliferation assays were performed using various cell types on PLA discs. Stromal-derived factor (SDF-1) release from cages filled with collagen was analyzed and the effect on endothelial cells tested. This study confirms the biocompatibility of PLA and demonstrates an endotoxin contamination clearly below the FDA (Food and Drug Administration) limit. Cells of various cell types (osteoblasts, osteoblast-like cells, fibroblasts and endothelial cells) grow, spread and proliferate on PLA-printed discs. PLA cages loaded with SDF-1 collagen display a steady SDF-1 release, support cell growth of endothelial cells and induce neo-vessel formation. These results demonstrate the potential for PLA scaffolds printed with an inexpensive desktop printer in medical applications, for example, in bone tissue engineering.


Assuntos
Colágeno Tipo I/química , Poliésteres/química , Regeneração Óssea/fisiologia , Linhagem Celular , Proliferação de Células/fisiologia , Quimiocina CXCL12/metabolismo , Humanos , Osteogênese/fisiologia , Engenharia Tecidual/métodos , Alicerces Teciduais/química
6.
Blood ; 120(8): 1691-702, 2012 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-22517899

RESUMO

Activating mutations in the receptor tyrosine kinase FLT3 are frequently found in acute myelogenous leukemia patients and confer poor clinical prognosis. It is unclear how leukemic blasts escape cytokine control that regulates normal hematopoiesis. We have recently demonstrated that FLT3-internal tandem duplication (ITD), when localized to the biosynthetic compartment, aberrantly activates STAT5. Here, we show that one of the target genes induced by STAT5 is suppressor of cytokine signaling (SOCS)1-a surprising finding for a known tumor suppressor. Although SOCS1 expression in murine bone marrow severely impaired cytokine-induced colony growth, it failed to inhibit FLT3-ITD-supported colony growth, indicating resistance of FLT3-ITD to SOCS1. In addition, SOCS1 coexpression did not affect FLT3-ITD-mediated signaling or proliferation. Importantly, SOCS1 coexpression inhibited interferon-α and interferon-γ signaling and protected FLT3-ITD hematopoietic cells from interferon-mediated growth inhibitory effects. In a murine bone marrow transplantation model, the coexpression of SOCS1 and FLT3-ITD significantly shortened the latency of a myeloproliferative disease compared with FLT3-ITD alone (P < .01). Mechanistically, SOCS proteins shield FLT3-ITD from external cytokine control, thereby promoting leukemogenesis. The data demonstrate that SOCS1 acts as a conditional oncogene, providing novel molecular insights into cytokine resistance in oncogenic transformation. Restoring cytokine control may provide a new way of therapeutic intervention.


Assuntos
Regulação Neoplásica da Expressão Gênica , Interferons/imunologia , Transtornos Mieloproliferativos/genética , Transtornos Mieloproliferativos/imunologia , Proteínas Supressoras da Sinalização de Citocina/genética , Tirosina Quinase 3 Semelhante a fms/genética , Animais , Linhagem Celular Tumoral , Células Cultivadas , Duplicação Gênica , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Transtornos Mieloproliferativos/patologia , Fator de Transcrição STAT5/genética , Fator de Transcrição STAT5/imunologia , Proteína 1 Supressora da Sinalização de Citocina , Proteínas Supressoras da Sinalização de Citocina/imunologia , Tirosina Quinase 3 Semelhante a fms/imunologia
7.
Front Bioeng Biotechnol ; 12: 1363380, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38595995

RESUMO

Introduction: Autologous platelet concentrate (APC) are pro-angiogenic and can promote wound healing and tissue repair, also in combination with other biomaterials. However, challenging defect situations remain demanding. 3D bioprinting of an APC based bioink encapsulated in a hydrogel could overcome this limitation with enhanced physio-mechanical interface, growth factor retention/secretion and defect-personalized shape to ultimately enhance regeneration. Methods: This study used extrusion-based bioprinting to create a novel bioink of alginate/cellulose hydrogel loaded with thrombocyte concentrate. Chemico-physical testing exhibited an amorphous structure characterized by high shape fidelity. Cytotoxicity assay and incubation of human osteogenic sarcoma cells (SaOs2) exposed excellent biocompatibility. enzyme-linked immunosorbent assay analysis confirmed pro-angiogenic growth factor release of the printed constructs, and co-incubation with HUVECS displayed proper cell viability and proliferation. Chorioallantoic membrane (CAM) assay explored the pro-angiogenic potential of the prints in vivo. Detailed proteome and secretome analysis revealed a substantial amount and homologous presence of pro-angiogenic proteins in the 3D construct. Results: This study demonstrated a 3D bioprinting approach to fabricate a novel bioink of alginate/cellulose hydrogel loaded with thrombocyte concentrate with high shape fidelity, biocompatibility, and substantial pro-angiogenic properties. Conclusion: This approach may be suitable for challenging physiological and anatomical defect situations when translated into clinical use.

8.
Haematologica ; 98(10): 1609-16, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23975178

RESUMO

Previous reports demonstrated a relationship between proliferation potential and trilineage differentiation in mesenchymal stromal cell-derived clones generated using plastic adherence (PA-MSCs). However, there are no reports presenting a clonal analysis of the proliferative potential, differentiation potential and allosuppressive effects of human mesenchymal stromal cell subsets. In this study, we performed a clonal analysis of mesenchymal stromal cells generated from human CD271(+) bone marrow mononuclear cells (CD271-MSCs). After transfection with the gene encoding green fluorescent protein, the cells were single-cell sorted and cultured for 2-4 weeks. A population doubling analysis demonstrated that 25% of CD271-MSC clones are fast-proliferating clones compared to only 10% of PA-MSC clones. Evaluation of the allosuppressive potential demonstrated that 81.8% of CD271-MSC clones were highly allosuppressive compared to only 58% of PA-MSC clones. However, no consistent correlation was observed between allosuppression and proliferative potential. Prostaglandin E2 levels were positively correlated with the allosuppressive activity of individual clones, suggesting that this molecule may be a useful predictive biomarker for the allosuppressive potential of mesenchymal stromal cells. In contrast, inhibitory studies of indoleamine 2,3 dioxygenase indicated that none of the clones used this enzyme to mediate their allosuppressive effect. Differentiation studies revealed the presence of tripotent, bipotent and unipotent CD271-MSC and PA-MSC clones which suppressed the allogeneic reaction to differing extents in vitro. In conclusion, our findings demonstrate differences between CD271-MSCs and PA-MSCs and indicate that neither proliferation potential nor differentiation potential represents a consistent predictive parameter for the immunomodulatory effects of either type of mesenchymal stromal cells.


Assuntos
Células da Medula Óssea/fisiologia , Técnicas de Cultura de Células/métodos , Tolerância Imunológica/fisiologia , Leucócitos Mononucleares/fisiologia , Células-Tronco Multipotentes/fisiologia , Proteínas do Tecido Nervoso/fisiologia , Receptores de Fator de Crescimento Neural/fisiologia , Células Cultivadas , Humanos , Células Estromais/fisiologia
9.
Nat Med ; 12(4): 401-9, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16582916

RESUMO

Gene transfer into hematopoietic stem cells has been used successfully for correcting lymphoid but not myeloid immunodeficiencies. Here we report on two adults who received gene therapy after nonmyeloablative bone marrow conditioning for the treatment of X-linked chronic granulomatous disease (X-CGD), a primary immunodeficiency caused by a defect in the oxidative antimicrobial activity of phagocytes resulting from mutations in gp91(phox). We detected substantial gene transfer in both individuals' neutrophils that lead to a large number of functionally corrected phagocytes and notable clinical improvement. Large-scale retroviral integration site-distribution analysis showed activating insertions in MDS1-EVI1, PRDM16 or SETBP1 that had influenced regulation of long-term hematopoiesis by expanding gene-corrected myelopoiesis three- to four-fold in both individuals. Although insertional influences have probably reinforced the therapeutic efficacy in this trial, our results suggest that gene therapy in combination with bone marrow conditioning can be successfully used to treat inherited diseases affecting the myeloid compartment such as CGD.


Assuntos
Proteínas de Transporte/genética , Proteínas de Ligação a DNA/genética , Terapia Genética/métodos , Doença Granulomatosa Crônica/terapia , Células-Tronco Hematopoéticas/fisiologia , Proteínas de Neoplasias/genética , Proteínas Nucleares/genética , Fatores de Transcrição/genética , Adulto , Cromossomos Humanos X , Ensaios Clínicos como Assunto , Técnicas de Transferência de Genes , Ligação Genética , Marcadores Genéticos , Vetores Genéticos , Doença Granulomatosa Crônica/sangue , Doença Granulomatosa Crônica/etiologia , Doença Granulomatosa Crônica/genética , Humanos , Proteína do Locus do Complexo MDS1 e EVI1 , Mutagênese Insercional , Neutrófilos/fisiologia , Proto-Oncogenes , RNA Mensageiro/análise , Retroviridae/genética , Resultado do Tratamento
10.
Clin Oral Investig ; 17(9): 2049-55, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23242815

RESUMO

OBJECTIVES: A selective intensified prevention (SIP) was introduced at individual schools in deprived areas in Marburg County (Germany) in 1995. The outcome of the program was evaluated in sixth graders (mean age: 12.06 years) in comparison to a control region. MATERIALS AND METHODS: Caries experience was recorded by applying International Caries Detection and Assessment System (ICDAS) II criteria. Tooth brushing habits and other independent variables were examined psychometrically. To compare the mean caries scores, non parametric tests were applied. The influence of various independent variables on caries experience was assessed by stepwise backward logistic regression analysis. The matching criteria age, gender, ethnicity and maternal education were used to parallelize the samples. RESULTS: ICDAS scores of 2-6 were detected uniformly more often in the control region than in the test group. Combining ICDAS scores 3-6, children from the control region (mean D(3-6)MFT: 1.73) showed roughly double the caries experience compared to the test group (mean D(3-6)MFT: 0.88, p < 0.005). The D(5,6)MFT score of the test group amounted to 0.50, and the corresponding value of the reference group was 0.77 (p = 0.043). Multivariate analysis disclosed fissure sealants, early start of tooth brushing and topical fluoride application to be associated with the prevention of dental caries. High frequency of sugar intake was associated with the presence of dentine lesions. CONCLUSIONS: The results of our study confirm the positive effect of SIP on the dental health of 12-year-old pupils living in deprived areas. CLINICAL RELEVANCE: On the basis of ICDAS II, targeted preventive measures can be applied in children with increased caries risk. Frequent applications of fluoride varnish inhibit the progression of initial lesions in this group.


Assuntos
Cárie Dentária/prevenção & controle , Serviços Preventivos de Saúde/normas , Criança , Alemanha , Humanos , Avaliação de Programas e Projetos de Saúde , Medição de Risco , Fatores de Risco , Inquéritos e Questionários
12.
Cells ; 11(19)2022 09 23.
Artigo em Inglês | MEDLINE | ID: mdl-36230931

RESUMO

Latent reservoirs in human-immunodeficiency-virus-1 (HIV-1)-infected individuals represent a major obstacle in finding a cure for HIV-1. Hematopoietic stem and progenitor cells (HSPCs) have been described as potential HIV-1 targets, but their roles as HIV-1 reservoirs remain controversial. Here we provide additional evidence for the susceptibility of several distinct HSPC subpopulations to HIV-1 infection in vitro and in vivo. In vitro infection experiments of HSPCs were performed with different HIV-1 Env-pseudotyped lentiviral particles and with replication-competent HIV-1. Low-level infection/transduction of HSPCs, including hematopoietic stem cells (HSCs) and multipotent progenitors (MPP), was observed, preferentially via CXCR4, but also via CCR5-mediated entry. Multi-lineage colony formation in methylcellulose assays and repetitive replating of transduced cells provided functional proof of susceptibility of primitive HSPCs to HIV-1 infection. Further, the access to bone marrow samples from HIV-positive individuals facilitated the detection of HIV-1 gag cDNA copies in CD34+ cells from eight (out of eleven) individuals, with at least six of them infected with CCR5-tropic HIV-1 strains. In summary, our data confirm that primitive HSPC subpopulations are susceptible to CXCR4- and CCR5-mediated HIV-1 infection in vitro and in vivo, which qualifies these cells to contribute to the HIV-1 reservoir in patients.


Assuntos
Infecções por HIV , HIV-1 , DNA Complementar , HIV-1/fisiologia , Células-Tronco Hematopoéticas , Humanos
13.
J Cell Biol ; 174(1): 27-38, 2006 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-16818717

RESUMO

Specific mammalian genes functionally and dynamically associate together within the nucleus. Yet, how an array of many genes along the chromosome sequence can be spatially organized and folded together is unknown. We investigated the 3D structure of a well-annotated, highly conserved 4.3-Mb region on mouse chromosome 14 that contains four clusters of genes separated by gene "deserts." In nuclei, this region forms multiple, nonrandom "higher order" structures. These structures are based on the gene distribution pattern in primary sequence and are marked by preferential associations among multiple gene clusters. Associating gene clusters represent expressed chromatin, but their aggregation is not simply dependent on ongoing transcription. In chromosomes with aggregated gene clusters, gene deserts preferentially align with the nuclear periphery, providing evidence for chromosomal region architecture by specific associations with functional nuclear domains. Together, these data suggest dynamic, probabilistic 3D folding states for a contiguous megabase-scale chromosomal region, supporting the diverse activities of multiple genes and their conserved primary sequence organization.


Assuntos
Mapeamento Cromossômico , Cromossomos de Mamíferos/química , Cromossomos de Mamíferos/genética , Genoma , Animais , Núcleo Celular/genética , Células Cultivadas , Cromatina/genética , Fibroblastos/metabolismo , Hibridização in Situ Fluorescente , Camundongos , Modelos Biológicos , Células NIH 3T3
14.
Circ Res ; 105(6): 537-44, 2009 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-19679834

RESUMO

RATIONALE: Endothelial progenitor cells (EPCs, defined as sca-1(+)flk-1(+)lin(-) mononuclear blood cells) contribute to vascular repair. The role of hypoxia and reactive oxygen species (ROS) in mobilization and function of these cells is incompletely understood. OBJECTIVE: We studied the contribution of the NADPH oxidase Nox2, an important vascular source of ROS in this context. METHODS AND RESULTS: Hypoxia (10% oxygen) induced the mobilization of EPCs in wild-type (WT) and Nox1 but not in Nox2 knockout (Nox2(y/-)) mice. As erythropoietin (EPO) is known to induce EPC mobilization, we focused on this hormone. EPO induced the mobilization of EPCs in WT and Nox1(y/-) but not Nox2(y/-) animals. Transplantation of bone marrow from Nox2(y/-) mice into WT-mice blocked mobilization in response to hypoxia and EPO, whereas transplantation of WT bone marrow into Nox2(y/-) mice restored mobilization. Reendothelialization of the injured mouse carotid artery was enhanced by hypoxia as well as by EPO, and this effect was not observed in Nox2(y/-) mice or after transplantation of Nox2(y/-) bone marrow. In cultured EPCs from WT but not Nox2(y/-) mice, EPO induced ROS production, migration, and proliferation. EPO signaling involves the STAT5 transcription factor. EPO-induced STAT5-dependent reporter gene expression was absent in Nox2-deficient cells. siRNA against the redox-sensitive phosphatase SHP-2 restored EPO-mediated STAT5 induction and inhibition of SHP-2 restored EPO-induced migration in Nox2-deficient cells CONCLUSIONS: We conclude that Nox2-derived ROS inactivate SHP-2 and thereby facilitate EPO signaling in EPCs to promote hypoxia-induced mobilization and vascular repair by these cells.


Assuntos
Células Endoteliais/enzimologia , Hipóxia/enzimologia , Leucócitos Mononucleares/enzimologia , Glicoproteínas de Membrana/metabolismo , NADPH Oxidases/metabolismo , Células-Tronco/enzimologia , Animais , Antígenos Ly , Transplante de Medula Óssea , Artérias Carótidas/enzimologia , Artérias Carótidas/patologia , Lesões das Artérias Carótidas/enzimologia , Lesões das Artérias Carótidas/genética , Lesões das Artérias Carótidas/patologia , Células Cultivadas , Células Endoteliais/patologia , Eritropoetina/metabolismo , Regulação da Expressão Gênica/genética , Hipóxia/genética , Hipóxia/patologia , Leucócitos Mononucleares/metabolismo , Leucócitos Mononucleares/patologia , Glicoproteínas de Membrana/genética , Proteínas de Membrana , Camundongos , Camundongos Knockout , NADH NADPH Oxirredutases/genética , NADH NADPH Oxirredutases/metabolismo , NADPH Oxidase 1 , NADPH Oxidase 2 , NADPH Oxidases/genética , Proteína Tirosina Fosfatase não Receptora Tipo 11/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Fator de Transcrição STAT5/metabolismo , Transdução de Sinais/genética , Células-Tronco/patologia , Receptor 2 de Fatores de Crescimento do Endotélio Vascular , Cicatrização/genética
15.
Redox Biol ; 47: 102133, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34562872

RESUMO

The respiratory burst of phagocytes is essential for human survival. Innate immune defence against pathogens relies strongly on reactive oxygen species (ROS) production by the NADPH oxidase (NOX2). ROS kill pathogens while the translocation of electrons across the plasma membrane via NOX2 depolarizes the cell. Simultaneously, protons are released into the cytosol. Here, we compare freshly isolated human polymorphonuclear leukocytes (PMN) to the granulocytes-like cell line PLB 985. We are recording ROS production while inhibiting the charge compensating and pH regulating voltage-gated proton channel (HV1). The data suggests that human PMN and the PLB 985 generate ROS via a general mechanism, consistent of NOX2 and HV1. Additionally, we advanced a mathematical model based on the biophysical properties of NOX2 and HV1. Our results strongly suggest the essential interconnection of HV1 and NOX2 during the respiratory burst of phagocytes. Zinc chelation during the time course of the experiments postulates that zinc leads to an irreversible termination of the respiratory burst over time. Flow cytometry shows cell death triggered by high zinc concentrations and PMA. Our data might help to elucidate the complex interaction of proteins during the respiratory burst and contribute to decipher its termination.


Assuntos
Neutrófilos , Explosão Respiratória , Humanos , Canais Iônicos/metabolismo , NADPH Oxidases/metabolismo , Neutrófilos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Zinco
16.
EMBO Mol Med ; 13(5): e13412, 2021 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-33755340

RESUMO

The tumor microenvironment in brain metastases is characterized by high myeloid cell content associated with immune suppressive and cancer-permissive functions. Moreover, brain metastases induce the recruitment of lymphocytes. Despite their presence, T-cell-directed therapies fail to elicit effective anti-tumor immune responses. Here, we seek to evaluate the applicability of radio-immunotherapy to modulate tumor immunity and overcome inhibitory effects that diminish anti-cancer activity. Radiotherapy-induced immune modulation resulted in an increase in cytotoxic T-cell numbers and prevented the induction of lymphocyte-mediated immune suppression. Radio-immunotherapy led to significantly improved tumor control with prolonged median survival in experimental breast-to-brain metastasis. However, long-term efficacy was not observed. Recurrent brain metastases showed accumulation of blood-borne PD-L1+ myeloid cells after radio-immunotherapy indicating the establishment of an immune suppressive environment to counteract re-activated T-cell responses. This finding was further supported by transcriptional analyses indicating a crucial role for monocyte-derived macrophages in mediating immune suppression and regulating T-cell function. Therefore, selective targeting of immune suppressive functions of myeloid cells is expected to be critical for improved therapeutic efficacy of radio-immunotherapy in brain metastases.


Assuntos
Neoplasias Encefálicas , Microambiente Tumoral , Neoplasias Encefálicas/radioterapia , Humanos , Imunoterapia , Macrófagos , Células Mieloides
17.
PLoS One ; 16(2): e0246527, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33577574

RESUMO

The aim of this study was to investigate the dynamic changes of circulating tumor cells (CTCs) in patients with hepatocellular carcinoma (HCC) before and immediately after conducting a microwave ablation (MWA) and conventional transarterial chemoembolization (C-TACE). Additionally, the CTCs short-term dynamics were compared with the clinical course of the HCC-patients. Blood samples from 17 patients with HCC who underwent MWA (n = 10) or C-TACE (n = 7) were analyzed. Venous blood was taken before and immediately after the radiological interventions to isolate and quantify CTCs using flow cytometry. CTCs were identified as CD45- and positive for the markers ASGPR, CD146 and CD274 (PD-L1). Patients were followed of up to 2.2 years after the radiological intervention. CTCs were detected in 13 HCC patients (76%) prior to the radiological interventions. The rate of CTCs was significantly decreased after the intervention in patients treated with MWA (0.4 CTCs/mL of blood, p = 0.031). However, no significant differences were observed in patients who received C-TACE (0.3 CTCs/mL of blood, p = 0.300). Overall, no correlation was found between the CTCs rate before and after the radiological intervention and recurrence rate of HCC. This preliminary data could confirm the tumoricidal effects of MWA in patients with HCC by significantly decreasing CTCs rate. In our study, we were able to detect CTCs in HCC patients using 3 different tumor markers. This preliminary data shows significant lower CTCs detected in response to MWA. However, large-scale randomized clinical trials are needed to determine the future role and the prognostic relevance of CTCs following this treatment.


Assuntos
Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Células Neoplásicas Circulantes/patologia , Idoso , Biomarcadores Tumorais/sangue , Antígeno CD146/metabolismo , Carcinoma Hepatocelular/sangue , Carcinoma Hepatocelular/terapia , Quimioembolização Terapêutica/métodos , Feminino , Humanos , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/terapia , Masculino , Micro-Ondas , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/terapia , Prognóstico
18.
Circ Res ; 103(11): 1327-34, 2008 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-18927463

RESUMO

Circulating blood-derived vasculogenic cells improve neovascularization of ischemic tissue by a broad repertoire of potential therapeutic actions. Whereas initial studies documented that the cells incorporate and differentiate to cardiovascular cells, other studies suggested that short-time paracrine mechanisms mediate the beneficial effects. The question remains to what extent a physical incorporation is contributing to the beneficial effects of cell therapy. By using the inducible suicide gene thymidine kinase to deplete transplanted cells, we determined the contribution of physical incorporation in 3 animal models. After acute myocardial infarction, depletion of cells 14 days after infusion resulted in a reduction of capillary density and a substantial deterioration of heart function. Likewise, neovascularization of Matrigel plugs and ischemic limbs was significantly suppressed when infused cells were depleted 7 days after infusion. Induction of cell death in the previously transplanted cells reduced perfusion and led to vascular leakage as evidenced by Evans blue extravasation. These results indicate that physical incorporation and persistence of cells contribute to cell-mediated improvement of neovascularization and cardiac function. Long-term paracrine activities and/or cell intrinsic mechanisms may have contributed to the maintenance of functional improvement.


Assuntos
Coração/fisiopatologia , Isquemia Miocárdica/terapia , Neovascularização Fisiológica/fisiologia , Transplante de Células-Tronco/métodos , Animais , Capilares/fisiopatologia , Técnicas de Cultura de Células , Terapia Baseada em Transplante de Células e Tecidos/métodos , Vasos Coronários/patologia , Feminino , Genes Reporter , Vetores Genéticos , Proteínas de Fluorescência Verde/genética , Humanos , Lentivirus , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/fisiologia , Imageamento por Ressonância Magnética , Camundongos , Camundongos Nus , Isquemia Miocárdica/fisiopatologia
19.
Stud Health Technol Inform ; 159: 272-6, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20543449

RESUMO

Adopting the world wide accessible Grid computing power and data management structures enables usage of large image data bases for individual diagnosis and therapy decisions. Here, we define several descriptors of the genome architecture of cell nuclei which are the basis of a detailed analysis for conclusions on the health state of an individual patient. All these descriptors can be accessed by automatic inspection of microscopic images of fluorescently labelled nuclei, obtained from cells from tissue sections or blood and subjected to standard biochemical protocols. We demonstrate how the combinatorial, geometrical and statistical parameters may be used in diagnosis and therapy monitoring.


Assuntos
Núcleo Celular/ultraestrutura , Redes de Comunicação de Computadores , Saúde , Medicina , Descritores , Núcleo Celular/genética , Fluorescência , Dosagem de Genes , Humanos , Imageamento Tridimensional
20.
iScience ; 23(6): 101178, 2020 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-32480132

RESUMO

Brain-resident microglia and bone marrow-derived macrophages represent the most abundant non-cancerous cells in the brain tumor microenvironment with critical functions in disease progression and therapeutic response. To date little is known about genetic programs that drive disease-associated phenotypes of microglia and macrophages in brain metastases. Here we used cytometric and transcriptomic analyses to define cellular and molecular changes of the myeloid compartment at distinct stages of brain metastasis and in response to radiotherapy. We demonstrate that genetic programming of tumor education in myeloid cells occurs early during metastatic onset and remains stable throughout tumor progression. Bulk and single cell RNA sequencing revealed distinct gene signatures in brain-resident microglia and blood-borne monocytes/macrophages during brain metastasis and in response to therapeutic intervention. Our data provide a framework for understanding the functional heterogeneity of brain metastasis-associated myeloid cells based on their origin.

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