978 resultados para IL-11
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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We generated transgenic mice expressing chimeric receptors, which comprise extracellular domains of the human granulocyte–macrophage colony-stimulating factor (hGM-CSF) receptor and transmembrane and cytoplasmic domains of the mouse leukemia inhibitory factor receptor. In suspension cultures of lineage-negative (Lin−), 5-fluorouracil-resistant bone marrow cells of the transgenic mice, a combination of hGM-CSF and stem cell factor (SCF) induced exponential expansions of mixed colony-forming unit. The combination of hGM-CSF and SCF was effective on enriched, Lin−Sca-1+c-kit+ progenitors and increased either mixed colony-forming unit or cobblestone area–forming cells. In case of stimulation with hGM-CSF and SCF, interleukin-6 (IL-6) and SCF, or IL-11 and SCF, the most efficient expansion was achieved with hGM-CSF and SCF. When Lin−Sca-1+c-kit+CD34− further enriched progenitors were clone sorted and individually incubated in the presence of SCF, hGM-CSF stimulated a larger number of cells than did IL-6, IL-6 and soluble IL-6 receptor (IL-6R), or IL-11. These data suggest the presence of IL-6Rα-, IL-11Rα-, and gp130-low to -negative primitive hematopoietic progenitors. Such primitive progenitors are equipped with signal transduction molecules and can expand when these chimeric receptors are genetically introduced into the cells and stimulated with hGM-CSF in the presence of SCF.
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Interleukin-11 (IL-11) is a pleiotropic cytokine that regulates the growth and development of hematopoietic stem cells and decreases the proinflammatory mediators of cytokine and nitric oxide production. In animal models of arthritis, treatment with recombinant human IL-11 (rhIL-11) reduces both the level of synovitis and the histologic lesion scores in the joints.
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Based on transplantation studies with bone marrow cultured under various conditions, a role of interleukin 11 (IL-11) in the self-renewal and/or the differentiation commitment of hematopoietic stem cells has been indicated. To better evaluate the in vivo effects of IL-11 on stem/progenitor cell biology, lethally irradiated mice were serially transplanted with bone marrow cells transduced with a defective retrovirus, termed MSCV-mIL-11, carrying the murine IL-11 (mIL-11) cDNA and the bacterial neomycin phosphotransferase (neo) gene. High serum levels (i.e., > 1 ng/ml) of mIL-11 in all (20/20) primary and 86% (12/14) of secondary long-term reconstituted mice, as well as 86% (12/14) of tertiary recipients examined at 6 weeks posttransplant, demonstrated persistence of vector expression subsequent to transduction of bone marrow precursors functionally definable as totipotent hematopoietic stem cells. In agreement with results obtained with human IL-11 in other myeloablation models, ectopic mIL-11 expression accelerated recovery of platelets, neutrophils, and, to some extent, total leukocytes while preferentially increasing peripheral platelet counts in fully reconstituted mice. When analyzed 5 months posttransplant, tertiary MSCV-mIL-11 recipients had a significantly greater percentage of G418-resistant colony-forming cells in their bone marrow compared with control MSCV animals. Collectively, these data show that persistent stimulation of platelet production by IL-11 is not detrimental to stem cell repopulating ability; rather, they suggest that IL-11 expression in vivo may have resulted in enhanced maintenance of the most primitive hematopoietic stem cell compartment. The prolonged expression achieved by the MSCV retroviral vector, despite the presence of a selectable marker, contrasts with the frequent transcriptional extinction observed with other retroviral vectors carrying two genes. These findings have potentially important implications for clinical bone marrow transplantation and gene therapy of the hematopoietic system.
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Leukemia inhibitory factor (LIF) and its receptor (LIFR) are "twins" of Oncostatin M (OSM) and OSMR, respectively, likely having arisen through gene duplications. We compared their effects in a bone nodule-forming model of in vitro osteogenesis, rat calvaria (RC) cell cultures. Using a dominant-negative LIF mutant (hLIF-05), we showed that in RC cell cultures mouse OSM (mOSM) activates exclusively glycoprotein 130 (gp130)/OSMR. In treatments starting at early nodule formation stage, LIF, mOSM, IL-11, and IL-6 + sIL-6R inhibit bone nodule formation, that is, osteoprogenitor differentiation. Treatment with mOSM, and no other cytokine of the family, in early cultures (day 1-3 or 1-4) increases bone colony numbers. hLIF-05 also dose dependently stimulates bone nodule formation, confirming the inhibitory action of gp130/LIFR on osteogenesis. In pulse treatments at successive stages of bone nodule formation and maturation, LIF blocks osteocalcin (OCN) expression by differentiated osteoblasts, but has no effect on bonesialoprotein (BSP) expression. Mouse OSM inhibits OCN and BSP expression in preconfluent cultures with no or progressively reduced effects at later stages, reflecting the disruption of early nodules, possibly due to the strong apoptotic action of mOSM in RC cell cultures. In summary, LIFR and OSMR display differential effects on differentiation and phenotypic expression of osteogenic cells, most likely through different signal transduction pathways. In particular, gp130/OSMR is the only receptor complex of the family to stimulate osteoprogenitor differentiation in the RC cell culture model. © 2005 Wiley-Liss, Inc.
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We have investigated the role of 23 candidate genes in the control of bone mineral density (BMD) by linkage studies in families of probands with osteoporosis (lumbar spine [LS] or femoral neck [FN] BMD T score < -2.5) and low BMD relative to an age- and gender-matched cohort (Z score < -2.0). One hundred and fifteen probands (35 male, 80 female) and 499 of their first- or second-degree relatives (223 males and 276 females) were recruited for the study. BMD was measured at the LS and FN using dual-energy X-ray absorptiometry and expressed as age- and gender-matched Z scores corrected for body mass index. The candidate genes studied were the androgen receptor, type I collagen A1 (COLIA1), COLIA2, COLIIA1, vitamin D receptor (VDR), colony-stimulating factor 1, calcium-sensing receptor, epidermal growth factor (EGF), estrogen receptor 1 (ESR1), fibrillin type 1, insulin-like growth factor 1, interleukin-1 alpha (IL-1α), interleukin-4 (IL-4), interleukin-6 (IL-6), interleukin-11 (IL-11), osteopontin, parathyroid hormone (PTH), PTH-related peptide, PTH receptor type 1 (PTHR1), transforming growth factor-beta 1, and tumor necrosis factors alpha and beta. Sixty-four microsatellites lying close to or within these genes were investigated for linkage with BMD. Using the program MapMaker/Sibs there was suggestive evidence of linkage between BMD and PTHR1 (maximum LOD score obtained [MLS] 2.7-3.5). Moderate evidence of linkage was also observed with EGF (MLS 1.8), COLIA1 (MLS 1.7), COLIIA1/VDR (MLS 1.7), ESR1 (MLS 1.4), IL-1α (MLS 1.4), IL-4 (MLS 1.2), and IL-6 (MLS 1.2). Variance components analysis using the program ACT, correcting for proband-wise ascertainment, also showed evidence of linkage (p ≤0.05) at markers close to or within the candidate genes IL- 1α, PTHR1, IL-6, and COLIIA1/VDR. Further studies will be required to confirm these findings, to refine the location of gene responsible for the observed linkage, and to screen the candidate genes targeted at these loci for mutations.
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Blastocyst implantation into the uterine endometrium establishes early pregnancy. This event is regulated by blastocyst- and/or endometrium-derived molecular factors which include hormones, growth factors, cell adhesion molecules, cytokines and proteases. Their coordinated expression and function are critical for a viable pregnancy. A rate-limiting event that immediately precedes implantation is the hatching of blastocyst. Ironically, blastocyst hatching is tacitly linked to peri-implantation events, although it is a distinct developmental phenomenon. The exact molecular network regulating hatching is still unclear. A number of implantation-associated molecular factors are expressed in the pre-implanting blastocyst. Among others, cytokines, expressed by peri-implantation blastocysts, are thought to be important for hatching, making blastocysts implantation competent. Pro-inflammatory (IL-6, LIF, GM-CSF) and anti-inflammatory (IL-11, CSF-1) cytokines improve hatching rates; they modulate proteases (MMPs, tPAs, cathepsins and ISP1). However, functional involvement of cytokines and their specific mediation of hatching-associated proteases are unclear. There is a need to understand mechanistic roles of cytokines and proteases in blastocyst hatching. This review will assess the available knowledge on blastocyst-derived pro-inflammatory and anti-inflammatory cytokines and their role in potentially regulating blastocyst hatching. They have implications in our understanding of early embryonic loss and infertility in mammals, including humans.
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Diffusible proteins regulate neural development at a variety of stages. Using a novel neuronal culture assay, I have identified several cytokines that regulate the expression of neurotransmitters and neuropeptides in sympathetic neurons. These cytokines fall into two families. The first group is termed the neuropoietic cytokines, while including CDF/LIF, CNTF, OSM and GPA, induces expression of the same set of neuropeptide mRNAs in cultured sympathetic neurons. These four factors not only exhibit similar biological activities; they also share a predicted secondary structure and bind to a signal-transducing receptor subunit in common with IL-6 and IL-11. The latter two cytokines display a weaker activity in this assay. In addition, I find that several members of the TGF-β superfamily, activin A, BMP-2, and BMP-6, have a selective overlap with the neuropoietic family in the spectrum of neuropeptides that these cytokines induce in sympathetic neurons. Different patterns of neuropeptides induced by the TGF-β family members, however, demonstrate that the activities of these cytokines are distinct from those of the neuropoietic family. Another 30 cytokines are without detectable effect in this neuronal assay.
Activin A induces a set of neurotransmitters and neuropeptides that is somewhat similar to the phenotype of sympathetic neurons innervating sweat glands in rat footpads. In situ hybridization and RNase protection were carried out to test whether activins were involved in the phenotypic transition when sympathetic neurons contact sweat glands. I find that activin mRNA is present in both cholinergic and noradrenergic targets. Moreover, homogenates of footpads do not contain activin-like activity in the neuronal assay in vitro. Taken together, these data do not support activins as the best candidates for the sweat gland factor.
Several novel factors that regulate neuropeptide expression exist in heart cell conditioned medium. I attempted to purify these factors in collaboration with Dr. Jane Talvenheimo. Our results suggest that these factors are sensitive to the storage conditions used. Several modifications of purification strategy are discussed.
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本论文研究工作的目的是使用透射电子显微镜技术和原子力显微镜技术来观察研究不同聚合物薄膜样品的微结构,包括结晶结构、表面微结构以及超分子结构。研究的意义在于更广泛和更深刻的理解聚合物凝聚态结构,建立聚合物结构与性能的内在联系。通过附生结晶的方法,第一次解决多年来间规聚丙烯亚稳晶型11难以单独熔体结晶获得的问题,得到了单晶。用电子衍射倾转技术结合计算机模拟技术,从分子水平上分析解释了同手性螺旋构象亚稳晶型Il附生机理和产生的原因,并确定了附生接触面是晶型11的晶面C110)_(II)。首次发现附生的控制因素除了样品和基底接触面之间的几何匹配外,两接触表面拓扑空间的一致性也是另一重要因素。首次用熔体结晶方法获得间规对氯聚苯乙烯的单晶。通过电子衍射技术和电子晶体学的研究,得到其单晶的晶胞参数为:a = 15.83A,b = 18.48A和c = 5.10A,空间群为Phnm 0并对其衍射进行计算机模拟,给出结晶结构的模型,确定了间规对一氯聚苯乙烯单晶的结晶结构和堆砌方式。同时一,本论文刘‘高密度聚乙烯高取向薄膜和氯代的聚芳醚酮单晶的表面微结构进行了分子级水平的研究,首次得到其表面的高分辨原子力图像。另外,本论文还对带有十二烷基侧链的聚对苯磺酸在溶液中形成的超分子结构—胶束的聚集态进行了研究,得到的关于胶束结构的信息与光散射数据相一致,第一次直观的观察到单根胶束的形貌。
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Nível de ação e o MIP-Soja. Ensaios com injúria na fase inicial da lavoura: Londrina, PR ? Safras 2001/2002 e 2002/2003. Ensaios com diferentes níveis de desfolha em diferentes fases do desenvolvimento: Não-Me-Toque-RS e Sorriso-MT ? Safra 2008/2009. Ensaios com diferentes níveis de desfolha contínua durante diferentes fases do desenvolvimento: Morrinhos, GO ? Safra 2009/2010. Resultados obtidos que comprovam a segurança dos níveis de ação recomendados. Considerações finais.
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2004
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Die Familie der IL-6-Typ-Zytokine (IL-6, IL-11, CT-1, CNTF, LIF, OSM, BSF-3) ist durch eine vierhelikale Faltung gekennzeichnet. Alle Zytokine dieser Familie agieren über einen Rezeptorkomplex, der als gemeinsame Komponente mindestens ein Molekül gp130 enthält. IL-6 und IL-11 signalisieren über ein gp130-Homodimer, während CT-1, CNTF, LIF und OSM ein Heterodimer aus gp130 und dem strukturell verwandten LIFR oder, im Falle des OSM, auch OSMR verwenden. Die Rezeptoren der vierhelikalen Zytokine sind in ihrem extrazellulären Bereich modulartig aus Ig- und Fibronektin-Typ-III-ähnlichen Domänen aufgebaut. Sie besitzen als gemeinsame Struktureinheit ein zytokinbindendes Modul (CBM) aus zwei Fibronektin-Typ-III-ähnlichen Domänen, die durch vier konservierte Cysteine in der N-terminalen und ein konserviertes WSXWS-Motiv in der C-terminalen Domäne charakterisiert sind. Auf Zielzellen bindet IL-6 an den spezifischen IL-6 Rezeptor, worauf der Komplex aus IL-6/IL-6R mit dem Signaltransduktor gp130 assoziiert. Der IL-6R besteht in seinem extrazellulären Bereich aus drei Domänen. Die N-terminale Ig-ähnliche Domäne ist für die biologische Aktivität nicht notwendig. Die Domänen 2 und 3 bilden das CBM, welches auch in löslicher Form agonistisch wirkt. In der vorliegenden Arbeit wurden die strukturellen und funktionellen Eigenschaften der dritten extrazellulären Domäne des IL-6R untersucht. Das Protein läßt sich effizient in Bakterien exprimieren und in vitro renaturieren. Es konnte gezeigt werden, daß Domäne 3 für die Bindung an IL-6 ausreichend ist, der Komplex aus D3 und IL-6 jedoch nicht mehr mit dem gp130-Molekül assoziieren kann. Da der lösliche IL-6R (bestehend aus D2 und D3) in der Lage ist, an gp130 zu binden und ein biologisches Signal auszulösen, weisen diese Daten der C-terminalen CBM-Domäne (D3) eine ligandenbindende Funktion und der N-terminalen CBM-Domäne eine wichtige Rolle bei der Komplexbildung mit gp130 und Signalinduktion zu. Die gezeigte Expressions- und Renaturierungsstrategie für D3 wurde zur Markierung des Proteins mit 15N und 13C für die mehrdimensionale, heteronukleare NMR-Spektroskopie angewandt. Die hierdurch ermöglichte Strukturaufklärung von D3 als einer eindeutig in die Ligandenbindung involvierten Teilstruktur wird umfassendere strukturelle Informationen über den IL-6R-Komplex liefern, als es die bisherigen Mutations- bzw. Modellbaustudien konnten.
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Platelets represent one of the largest storage pools of angiogenic and oncogenic growth factors in the human body. The observation that thrombocytosis (platelet count >450,000/uL) occurs in patients with solid malignancies was made over 100 years ago. However, the clinical and biological implications as well as the underlying mechanism of paraneoplastic thrombocytosis associated with ovarian carcinoma remains unknown and were the focus of the current study. Following IRB approval, patient data were collected on 619 patients from 4 U.S. centers and used to test associations between platelet count at initial diagnosis, clinicopathologic factors, and outcome. In vitro effects of plasma-purified platelets on ovarian cancer cell proliferation, docetaxel-induced apoptosis, and migration were evaluated using BrdU-PI flow cytometric and two-chamber chemotaxis assays. In vivo effects of platelet depletion on tumor growth, proliferation, apoptosis, and angiogenesis were examined using an anti-platelet antibody (anti-mouse glycoprotein 1ba, Emfret) to reduce platelets by 50%. Complete blood counts and number of mature megakaryocytes in the spleen and bone marrow were compared between control mice and ovarian cancer-bearing mice. Plasma levels of key megakaryo- and thrombopoietic factors including thrombopoietin (TPO), IL-1a, IL-3, IL-4, IL-6, IL-11, G-CSF, GM-CSF, stem cell factor, and FLT-3 ligand were assayed in a subset of 150 patients at the time of initial diagnosis with advanced stage, high grade epithelial ovarian cancer using immunobead-based cytokine profiling coupled with the Luminex® xMAP platform. Plasma cytokines significantly associated with thrombocytosis in ovarian cancer patients were subsequently evaluated in mouse models of ovarian cancer using ELISA immunoassays. The results of human and mouse plasma cytokine profiling were used to inform subsequent in vivo studies evaluating the effect of siRNA-induced silencing of select megakaryo- and thrombopoietic cytokines on paraneoplastic thrombocytosis. Thirty-one percent of patients had thrombocytosis at initial diagnosis. Compared to patients with normal platelet counts, women with thrombocytosis were significantly more likely to have advanced stage disease (p<0.001) and poor median progression-free (0.94 vs 1.35 years, p<0.001) and overall survival (2.62 vs 4.65 years, p<0.001). On multivariate analysis, thrombocytosis remained an independent predictor of decreased overall survival. Our analysis revealed that thrombocytosis significantly increases the risk of VTE in ovarian cancer patients and that thrombocytosis is an independent predictor of increased mortality in women who do develop a blood clot. Platelets increased ovarian cancer cell proliferation and migration by 4.1- and 2.8-fold (p<0.01), respectively. Platelets reduced docetaxel-induced apoptosis in ovarian cancer cells by 2-fold (p<0.001). In vivo, platelet depletion reduced tumor growth by 50%. Staining of in vivo specimens revealed decreased tumor cell proliferation (p<0.001) and increased tumor and endothelial cell apoptosis (p<0.01). Platelet depletion also significantly decreased microvessel density and pericyte coverage (p<0.001). Platelet counts increase by 31-130% in mice with invasive ovarian cancer compared to controls (p<0.01) and strongly correlate with mean megakaryocyte counts in the spleen and bone marrow (r=0.95, p<0.05). Plasma levels of TPO, IL-6, and G-CSF were significantly increased in ovarian cancer patients with thrombocytosis. Plasma levels of the same cytokines were found to be significantly elevated in orthotopic mouse models of ovarian cancer, which consistently develop paraneoplastic thromocytosis. Silencing TPO, IL-6, and G-CSF significantly abrogated paraneoplastic thrombocytosis in vivo. This study provides new understanding of the clinical and biological significance of paraneoplastic thrombocytosis in ovarian cancer and uncovers key humoral factors driving this process. Blocking the development of paraneoplastic thrombocytosis and interfering with platelet-cancer cell interactions could represent novel therapeutic strategies.