共查询到20条相似文献,搜索用时 31 毫秒
1.
2.
3.
Activation of interleukin-6 gene expression through the NF-kappa B transcription factor. 总被引:65,自引:14,他引:51 下载免费PDF全文
The promoter region of the interleukin-6 (IL-6) gene has a putative NF-kappa B-binding site. We found that a fragment of the IL-6 promoter containing the site specifically binds highly purified NF-kappa B protein and the NF-kappa B protein in nuclear extracts of phorbol ester-induced Jurkat cells. Mutations of the NF-kappa B site abolished complex formation with both purified NF-kappa B and the nuclear extract protein. Transient expression of chloramphenicol acetyltransferase (CAT) plasmids containing the IL-6 promoter revealed very little activity of the promoter in U-937 monocytic cells and in HeLa cells before stimulation. However, stimulation of U-937 and HeLa cells by inducers of NF-kappa B led to a dramatic increase in CAT activity. Mutations in the NF-kappa B-binding site abolished inducibility of IL-6 promoter-cat constructs in U-937 cells by lipopolysaccharide, tumor necrosis factor alpha, the double-stranded RNA poly(IC), or phytohemagglutinin and in HeLa cells by tumor necrosis factor alpha and drastically reduced but did not completely eliminate inducibility in HeLa cells stimulated by double-stranded RNA poly(IC) or phorbol 12-myristate 13-acetate. These results suggest that NF-kappa B is an important mediator for activation of the IL-6 gene by a variety of IL-6 inducers in both U-937 and HeLa cells and that alternative inducible enhancer elements contribute in a cell-specific manner to IL-6 gene induction. Because NF-kappa B is involved in the control of a variety of genes activated upon inflammation, NF-kappa B may play a central role in the inflammatory response to infection and tissue injury. 相似文献
4.
5.
6.
7.
A Simbirtsev E Prokopieva E Ivanova V Konusova N D Perumov S Ketlinsky 《European cytokine network》1992,3(4):421-428
Human IL-1 beta and TNF alpha production by normal and transformed monocytoid cells was studied using biological assays, cytokine specific ELISA and by immunocytochemical methods on a single cell level. Quiescent human blood monocytes and cultured in vitro transformed human monocytoid cell lines U-937, THP-1 and HL-60 did not contain IL-1 beta and TNF alpha in their cytoplasm. IL-1 beta synthesis and secretion was induced by LPS stimulation in nearly 90% monocytes, 15-20% U-937, 3-5% THP-1 and in no HL-60 cells. Normal human blood monocytes had a more rapid kinetics of IL-1 beta synthesis. IL-1 beta positive cells stained with antibodies to human IL-1 beta appeared at 1-2 hours after LPS application, while in monocytic cell lines only after 4-6 hours. Using immunoperoxidase staining of U-937 cells pulse labelled with 3H-thymidine, it was shown that proliferating cells did not synthetize IL-1 beta. Instead of IL-1 beta, TNF alpha could be induced by LPS in U-937 cells only after preliminary differentiation with PMA. Recombinant IL-1 beta induced a very low level of TNF alpha production in PMA-treated cells. Similarly recombinant TNF alpha alone induced IL-1 beta synthesis only in a few U-937 cells. 相似文献
8.
D L Fagan J L Prehn J S Adams S C Jordan 《Molecular endocrinology (Baltimore, Md.)》1991,5(2):179-186
The active metabolite of vitamin D, 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3], is a potent regulator of human monocyte/macrophage function in vitro. To establish a model for 1,25-(OH)2D3 regulation of human monocyte monokine synthesis, three human cell lines (U-937, THP-1, and HL-60) were examined for: 1) the presence of functional 1,25-(OH)2D3 receptors; 2) the accumulation of interleukin-1 beta (IL-1 beta) mRNA and IL-1 beta protein in response to lipopolysaccharide (LPS); and 3) the regulation of this response by 1,25-(OH)2D3. All three cell lines expressed vitamin D receptor and had increased levels of IL-1 beta mRNA in response to LPS. Preincubation of cells with 1,25-(OH)2D3 augmented IL-1 beta mRNA levels only in U-937 and HL-60 cells. From these data, and taking into consideration their state of differentiation and relative ease of culture, U-937 was chosen over HL-60 and THP-1 as the cell line we further characterized. In U-937 cells, optimum time and dose of pretreatment with 1,25-(OH)2D3 were determined to be 12-24 h at a receptor saturating concentration of 1,25-(OH)2D3 (10 nM). Preincubation of cells with 1,25-(OH)2D3 had no effect on the time course of IL-1 beta mRNA appearance in response to LPS. However, exposure of U-937 cells to 1,25-(OH)2D3 increased by 200% the level of IL-1 beta mRNA detected and decreased by three orders of magnitude the concentration of LPS required to achieve steady state mRNA levels equivalent to those observed in U-937 cells not preincubated with the hormone.2+o 相似文献
9.
M I Wickremasinghe L H Thomas J S Friedland 《Journal of immunology (Baltimore, Md. : 1950)》1999,163(7):3936-3947
10.
11.
12.
13.
The objective of this study was to elucidate the role of the cellular proteasome on endotoxin-mediated activation of the macrophage. To study this role, THP-1 cells were stimulated with lipopolysaccharide (LPS) with selective cells being pretreated with the proteasome inhibitor, lactacystin or MG-132. LPS stimulation led to the phosphorylation and degradation of IRAK, followed by activation of JNK/SAPK, ERK 1/2, and p38. Subsequently, LPS induced the degradation of IkappaB, and the nuclear activation of NF-kappaB and AP-1. Activation of these pathways was associated with the production of IL-6, IL-8, IL-10, and TNF-alpha. Proteasome inhibition with either lactacystin or MG-132 attenuated LPS-induced IRAK degradation, and enhanced activation of JNK/SAPK, ERK 1/2, and p38. Proteasome inhibition, also, led to increased LPS-induced AP-1 activation, and attenuated LPS-induced IkappaB degradation resulting in abolished NF-kappaB activation. Proteasome inhibition led to significant modulation of LPS-induced cytokine production; increased IL-10, no change in IL-6, and decreased IL-8, and TNF-alpha. Thus, this study demonstrates that cellular proteasome is critical to regulation of LPS-induced signaling within the macrophage, and inhibition of the proteasome results in a conversion to an anti-inflammatory phenotype. 相似文献
14.
A CRE/ATF-like site in the upstream regulatory sequence of the human interleukin 1 beta gene is necessary for induction in U937 and THP-1 monocytic cell lines. 下载免费PDF全文
J G Gray G Chandra W C Clay S W Stinnett S A Haneline J J Lorenz I R Patel G B Wisely P J Furdon J D Taylor et al. 《Molecular and cellular biology》1993,13(11):6678-6689
15.
Skerrett SJ Liggitt HD Hajjar AM Ernst RK Miller SI Wilson CB 《American journal of physiology. Lung cellular and molecular physiology》2004,287(1):L143-L152
To determine the role of respiratory epithelial cells in the inflammatory response to inhaled endotoxin, we selectively inhibited NF-kappa B activation in the respiratory epithelium using a mutant I kappa B-alpha construct that functioned as a dominant negative inhibitor of NF-kappa B translocation (dnI kappa B-alpha). We developed two lines of transgenic mice in which expression of dnI kappa B-alpha was targeted to the distal airway epithelium using the human surfactant apoprotein C promoter. Transgene expression was localized to the epithelium of the terminal bronchioles and alveoli. After inhalation of LPS, nuclear translocation of NF-kappa B was evident in bronchiolar epithelium of nontransgenic but not of transgenic mice. This defect was associated with impaired neutrophilic lung inflammation 4 h after LPS challenge and diminished levels of TNF-alpha, IL-1 beta, macrophage inflammatory protein-2, and KC in lung homogenates. Expression of TNF-alpha within bronchiolar epithelial cells and of VCAM-1 within peribronchiolar endothelial cells was reduced in transgenic animals. Thus targeted inhibition of NF-kappa B activation in distal airway epithelial cells impaired the inflammatory response to inhaled LPS. These data provide causal evidence that distal airway epithelial cells and the signals they transduce play a physiological role in lung inflammation in vivo. 相似文献
16.
17.
Glutamine decreases lipopolysaccharide-induced IL-8 production in Caco-2 cells through a non-NF-kappaB p50 mechanism 总被引:1,自引:0,他引:1
Glutamine (Gln) supplementation has been shown to decrease production of pro-inflammatory cytokines by the human intestinal mucosa. The mechanism of this is poorly understood. We hypothesize that Gln down-regulates lipopolysaccharide (LPS)-stimulated pro-inflammatory cytokine production in Caco-2 cells by nuclear factor-kappa B (NF-kappaB). Caco-2 cells were incubated with different concentrations of Gln with or without methionine sulfoximine (MS, an inhibitor of glutamine synthetase) before stimulation with LPS. IL-6, IL-8, IL-10 and TNF-alpha protein and mRNA level were determined. NF-kappaB translocation was determined using an ELISA-based kit. IL-8 was the only detectable cytokine/chemokine. The largest amount of IL-8 was secreted by cells in the presence of MS with no Gln in the medium after exposure to LPS. LPS increased IL-8 production, peaking 10h after LPS administration. The addition of Gln (0.5 or 5.0mM) decreased IL-8 peptide and mRNA expression. LPS increased NF-kappaB nuclear translocation in the presence or absence of MS. Neither Gln nor MS altered NF-kappaB nuclear translocation. These results indicate that the lack of glutamine increases IL-8 production by Caco-2 cells after LPS stimulation. However, the glutamine-mediated decrease in LPS-stimulated IL-8 production is not associated with NF-kappaB p50 nuclear binding. 相似文献
18.
19.
20.
Azithromycin suppresses interleukin-12p40 expression in lipopolysaccharide and interferon-γ stimulated macrophages 下载免费PDF全文
Keiko Yamauchi Yoko Shibata Tomomi Kimura Shuichi Abe Sumito Inoue Daisuke Osaka Michiko Sato Akira Igarashi Isao Kubota 《International journal of biological sciences》2009,5(7):667-678