Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04141 (granulocyte-macrophage colony-stimulating factor)
 6,790 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The CD95 (Fas/APO-1) apoptosis receptor is expressed in a variety of tissues and transiently upregulated in lymphocytes during activation-induced cell death. A silencer (S1; -1035 to -1008) and an adjacent enhancer (E1; -1007 to -964) region have been mapped in the CD95 gene. The S1 region shows similarity to binding sites for the transcriptional repressor NF-GMb, which prefers binding to single-stranded DNA. The E1 contains an everted repeat of two CATTA/T elements spaced by 2 bp (ER2). Such motifs are directly repeated in the CLE0 region of the human granulocyte-macrophage colony-stimulating factor (huGM-CSF) promoter. A motif (TGATGTCA) which matches a CREB site and is similar to an AP-1 site is embedded within ER2. Sequence-specific binding of nuclear factors to single-stranded S1 probes involved, to some extent, a central heptamer motif (ATCCAAA) also present in E1. Competition binding studies suggested that AP-1 or AP-1 components, as well as factors related, but not identical, to NF-AT bound to E1 probes. S1-binding-proteins/complexes of 47, 77, and 100 kDa were detected by Southwestern analysis and ultraviolet crosslinking. Complexes of 70 and 80 kDa were formed with a double-stranded E1 probe in UV-crosslinking, whereas Southwestern analysis with this probe revealed single binding species of 59 and 113 kDa. ER2 autonomously enhanced transcription from the heterologous HSV tk promoter in a cell type-specific manner only in the absence of the S1 region. This analysis has identified a small region in the CD95 gene containing adjacent opposing regulatory elements which are likely to be involved in the cell type- and activation state-specific gene expression under physiologic conditions.
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PMID:Silencer and enhancer regions in the human CD95 (Fas/APO-1) gene with sequence similarity to the granulocyte-macrophage colony-stimulating factor promoter: binding of single strand-specific silencer factors and AP-1 and NF-AT-like enhancer factors. 988 66

The current study was undertaken to evaluate the effects of granulocyte-macrophage colony-stimulating factor (GM-CSF) and cyclic AMP (cAMP) signaling interaction on human neutrophil apoptosis, either occurring spontaneously or induced by Fas antigen activation. Results show that GM-CSF, dibutyryl cAMP (a cAMP analog) and forskolin (an adenylate cyclase activator) are all able to suppress spontaneous neutrophil cell death. Of note however, when GM-CSF is used in combination with cAMP-elevating agents, an additive effect on neutrophil survival is observed with dibutyryl cAMP only, whereas supplementation of cell cultures with GM-CSF and forskolin results in a progressive reduction of antiapoptotic effects exerted by the single compounds. Moreover, although dibutyryl cAMP and forskolin do not affect Fas-triggered apoptotic events, they are still able to modulate the GM-CSF capacity to prolong neutrophil survival following anti-Fas IgM cell challenge, with effects similar to those respectively exerted on spontaneous neutrophil apoptosis. The data indicate that GM-CSF may negatively modulate the cAMP-mediated antiapoptotic pathway in human neutrophils, likely via the inhibition of adenylate cyclase activity. This would prevent an abnormal neutrophil survival as a result of cAMP signaling stimulation, which provides a novel insight into the role of GM-CSF as a physiological regulator of myeloid cell turnover.
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PMID:Effects of granulocyte-macrophage colony-stimulating factor and cyclic AMP interaction on human neutrophil apoptosis. 992 31

The mechanisms through which immune and inflammatory responses stimulate the expression of antimycobacterial activity by human macrophages remain poorly defined. To study this question, we developed a method permitting the rapid quantification of viable mycobacteria, based on the detection of luciferase activity expressed by a Mycobacterium bovis Bacillus Calmette-Guerin (BCG) reporter strain, and used this approach to evaluate mycobacterial survival in human monocyte-derived macrophages following stimulation with cytokines and through crosslinking of costimulatory molecules expressed on the cell surface. Modest proliferation, followed by persistence of mycobacteria, was observed in unpretreated macrophages as assessed both by measurement of luciferase activity and by the evaluation of colony forming units. Of the 19 cytokines tested, only granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-3 (IL-3) were found to improve the mycobactericidal activity of monocyte-derived macrophages. In both cases, this effect was observed only when macrophages were pretreated with the cytokines prior to infection. In contrast, pretreatment of human macrophages with interferon-gamma, either alone or in combination with other mediators (including tumor necrosis factor-alpha and 1,25[OH]2-vitamin D3), did not improve mycobacterial killing. The stimulation of macrophages through several different costimulatory molecules known to participate in macrophage-lymphocyte interactions (CD4, CD40, CD45, CD86, CD95 [Fas/Apo-1]) also failed to improve mycobactericidal activity. This study shows that GM-CSF and IL-3, cytokines whose receptors are known to share a common subunit and to use common second messengers, may contribute to the stimulation of mycobactericidal activity in humans. The ability to rapidly screen the effects of different macrophage stimuli on mycobacterial survival through the detection of luciferase activity should help define additional signals required for optimal antimycobacterial responses.
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PMID:Effect of stimulation of human macrophages on intracellular survival of Mycobacterium bovis Bacillus Calmette-Guerin. Evaluation with a mycobacterial reporter strain. 1022 37

Neutrophil function defects occur in individuals with Down syndrome (DS). We examined apoptosis of granulocytes (neutrophils and eosinophils) in DS individuals and control healthy subjects. Granulocyte survival was shortened in DS individuals, and the percentage of apoptotic granulocytes from DS during incubation was significantly higher than that from healthy subjects. The difference was time-dependent, and that between DS and healthy subjects was nearly 30% after longer periods of incubation. In control granulocytes, both granulocyte-macrophage colony-stimulating factor (10 ng/ml) and interleukin-5 (5 ng/ml) counteracted the programmed cell death and delayed the apoptosis caused by anti-Fas antibodies, whereas those inflammatory cytokines were not able to completely prevent cellular apoptosis in DS patients. Apoptosis and functional impairment of granulocytes may contribute to the risk of infections underlying pathological conditions of DS, and accelerated apoptosis of granulocytes may be a factor to prevent chronic airway inflammation and bronchial asthma in DS individuals.
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PMID:Presenility of granulocytes in Down syndrome individuals. 1036 Mar 94

Human granulocyte-macrophage colony-stimulating factor fused to truncated diphtheria toxin (DT388-GM-CSF) sensitized wild-type and Bcl2-overexpressing HL60 human leukemia cells to intoxication by Ara-C based on proliferation and clonogenic assays. The toxin/drug combination showed dramatic synergistic toxicity with combination indices of < 0.1. Synergy was not seen with two other protein synthesis inhibiting drugs--ricin and cycloheximide nor with GMCSF alone. No changes in Ara-C incorporation into cellular DNA or cell cycle occupancy were seen. As compared to exposure to DT388-GM-CSF or Ara-C alone, co-treatment produced significant increases in cytosolic accumulation of cytochrome c, a higher percentage of cells with loss of mitochondrial membrane potential and an increase in reactive oxygen species and morphologic changes of apoptosis, and a greater induction of poly(ADP-ribose) polymerase (PARP) and DNA fragmentation factor 45 (DFF45) cleavage activities of caspase 3. Co-treatment did not significantly alter Bcl2, Bcl-xL, Bax or Fas receptor (FasR), but modestly increased Fas ligand (FasL) protein. These finding suggest that co-treatment with DT388-GM-CSF may lead to a lowered apoptotic threshold and clonogenic survival of human AML blasts due to Ara-C. These observations also suggest that clinical trials of combination therapy may be warranted in patients with AML.
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PMID:Diphtheria toxin fused to granulocyte-macrophage colony-stimulating factor and Ara-C exert synergistic toxicity against human AML HL-60 cells. 1037 46

Tumors, such as the murine Lewis lung carcinoma (LLC), produce granulocyte-macrophage colony-stimulating factor (GM-CSF), which increases the proportion of CD34(+) hematopoietic progenitor cells in the bone marrow and in the periphery. This increase in peripheral CD34(+) cells had been attributed to the growth-promoting and mobilizing effects of the tumor-derived GM-CSF. However, the possibility that the CD34(+) cells of tumor bearers might have enhanced survival abilities had not been considered. The present studies showed a significant baseline level of apoptotic cells in short-term (5-day) cultures of normal CD34(+) cells containing GM-CSF plus stem cell factor (SCF), and a markedly greater level of apoptosis in cytokine-deficient cultures. In contrast, CD34(+) cells from tumor bearers did not undergo such levels of apoptosis, even in the absence of cytokines. This resistance to apoptosis could be conferred to normal CD34(+) cells by culture with LLC-conditioned medium. Studies to elucidate possible mechanisms for the resistance to apoptosis by tumor-exposed CD34(+) cells showed increased levels of the pro-life gene product bcl-2. Finally, the resistance of tumor-exposed CD34(+) cells to ligation of the Fas receptor, a known apoptotic trigger in hematopoietic cells, was compared with that of control CD34(+) cultures. Whereas approximately half of the normal CD34(+) cells underwent apoptosis in response to Fas ligation, the tumor-exposed CD34(+) cells resisted apoptosis, even though their surface Fas expression was greater than that of normal CD34(+) cells. Thus, our results show that the increased level of CD34(+) cells in tumor bearers is due not only to an increased growth and mobilization of CD34(+) cells as previously thought, but also may be due to an increased resistance to apoptosis that is conferred by tumor-derived products and is associated with increased expression of bcl-2.
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PMID:Increased resistance to apoptosis by bone marrow CD34(+)progenitor cells from tumor-bearing mice. 1040 79

T-cell apoptosis is a mechanism regulating T-cell homeostasis. Activation renders T cells susceptible to activation-induced cell death, a process mediated through CD95 ligand/CD95 (Apo-1/Fas) ligation. The aim of this study was to test whether antigen-presenting cells can inhibit CD95/Fas-triggered activation-induced cell death. Dendritic cells (DC), which are highly effective antigen-presenting cells, were generated in vitro from human peripheral blood monocytes by culture in granulocyte-macrophage colony-stimulating factor and interleukin 4. Subsequently, DC were cocultured with activated T cells and the effect of DC on CD95/Fas-mediated apoptosis was determined. Coculture with increasing amounts of DC prevented CD95/Fas-triggered apoptosis in a dose-dependent fashion by inhibiting activation of caspase 8 and caspase 3. This protective effect of the DC on T-cell death could be blocked by 50% by adding an anti-CD58 antibody, whereas further addition of anti-CD80 (B7.1) and anti-CD86 (B7.2) led to an even more pronounced effect. Our findings suggest that DC can protect T cells from activation-induced cell death, with CD58 ligation playing a key role.
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PMID:CD95/Fas-triggered apoptosis of activated T lymphocytes is prevented by dendritic cells through a CD58-dependent mechanism. 1048 Apr 31

Neutrophil apoptosis is important for the resolution of airway inflammation in a number of lung diseases. Inflammatory mediators, endogenous reactive oxygen and nitrogen species, and intracellular and extracellular antioxidants may all influence neutrophil apoptosis. This study investigated the involvement of these factors during apoptosis of neutrophils cultured in vitro. Neutrophils undergoing spontaneous apoptosis in culture as assessed by annexin V binding generated significant amounts of nitrite. Incubation with agonistic anti-Fas monoclonal antibody or tumor necrosis factor-alpha (TNF-alpha) enhanced neutrophil apoptosis at 6 h, although it decreased nitrite accumulation. Although granulocyte-macrophage colony-stimulating factor significantly reduced neutrophil apoptosis, this was also associated with decreased nitrite accumulation. In contrast, inhibition of apoptosis at 16 h by dibutyryl cyclic adenosine monophosphate was associated with increased nitrite accumulation. Exogenous glutathione (GSH) or N-acetylcysteine significantly enhanced neutrophil apoptosis at 6 h and stimulated the production of H(2)O(2), which may mediate apoptosis through intracellular hydroxyl radical production. Intracellular GSH concentrations decreased in neutrophils undergoing apoptosis, and this was more marked in neutrophils treated with anti-Fas or TNF-alpha. These results suggest a causal association between reduced endogenous nitric oxide production, reduced intracellular GSH, and Fas- and TNF-alpha-mediated neutrophil apoptosis, whereas enhanced neutrophil survival mediated by dibutyryl cyclic adenosine monophosphate is associated with increased nitrite generation and maintenance of intracellular GSH. The interaction of endogenous reactive oxygen species with extracellular antioxidants such as GSH could also contribute to the complex processes regulating neutrophil apoptosis and hence the resolution of inflammation in the lung.
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PMID:Nitrite generation and antioxidant effects during neutrophil apoptosis. 1080 25

Apoptosis and clearance of neutrophils is essential for successful resolution of inflammation. Altered signaling via the Fas receptor could explain the observed prolongation of neutrophil lifespan and associated tissue injury at inflammatory sites. We therefore compared inflammatory neutrophils extracted from joints of rheumatoid arthritis patients, with peripheral blood neutrophils. Inflammatory neutrophils underwent constitutive apoptosis in culture more rapidly than peripheral blood neutrophils; this was not explained by changes in surface expression of Fas or by induction of Fas ligand. Inflammatory neutrophils remained sensitive to Fas-induced death, at levels comparable to those seen in peripheral blood neutrophils. Similarly, granulocyte-macrophage colony-stimulating factor reduced apoptosis but did not abolish signaling via Fas. These data provide evidence for the rate of apoptosis in inflammatory neutrophils being continually modulated by death and survival signals in the inflammatory milieu. This allows for rapid resolution of inflammation as levels of survival factors fall, and suggests new strategies for inducing resolution of inflammation.
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PMID:Inflammatory neutrophils retain susceptibility to apoptosis mediated via the Fas death receptor. 1081 Oct 6

Acute pancreatitis (AP) may lead to the development of multiple organ dysfunction syndrome (MODS), especially in severe cases. Resolution of such inflammatory responses is dependent on neutrophil apoptosis. Delays in this apoptotic response are associated with persistent inflammation and subsequent tissue damage. The aim of this study is to determine the effects of AP on neutrophil apoptosis and to investigate the underlying mechanisms involved. Neutrophils and serum were isolated from control (n=10) and from patients with AP (mild, n=35, and severe, n=5). Neutrophil apoptosis was assessed by propidium iodide DNA staining using flow cytometry. Caspase, glutathione-S-transferase (GST), and Mcl-1 protein expression were assessed by SDS-PAGE western blotting. Serum interleukin (IL)-1beta and granulocyte-macrophage colony-stimulating factor (GM-CSF) levels were measured by ELISA. Neutrophils isolated from patients with AP show a significant delay in spontaneous neutrophil apoptosis. Serum factors contributed to this delay with increases in IL-1beta and GM-CSF. Isolated neutrophils were resistant to Fas antibody-induced apoptosis. Caspases represent a central mechanism for spontaneous and Fas antibody-induced neutrophil apoptosis. Procaspase 3 expression was decreased in mild and severe cases, but this effect was independent of serum factors. Increases in GST expression may also contribute to the antiapoptotic effect. Altered caspase expression may represent an additional factor contributing to delayed neutrophil apoptosis. This may contribute to the development of AP and its related complications.
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PMID:Altered caspase expression results in delayed neutrophil apoptosis in acute pancreatitis. 1091 85


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